#+TITLE: Jastrow Factor

#+SETUPFILE: ../tools/theme.setup
#+INCLUDE: ../tools/lib.org

* Introduction

  The Jastrow factor depends on the electronic ($\mathbf{r}$) and
  nuclear ($\mathbf{R}$) coordinates. Its defined as $\exp(J(\mathbf{r},\mathbf{R}))$, where

  \[
  J(\mathbf{r},\mathbf{R}) = J_{\text{eN}}(\mathbf{r},\mathbf{R}) + J_{\text{ee}}(\mathbf{r}) + J_{\text{eeN}}(\mathbf{r},\mathbf{R})
  \]
  
  In the following, we use the notations $r_{ij} = |\mathbf{r}_i - \mathbf{r}_j|$ and
  $R_{i\alpha} = |\mathbf{r}_i - \mathbf{R}_\alpha|$.

  $J_{\text{eN}}$ contains electron-nucleus  terms:

  \[
  J_{\text{eN}}(\mathbf{r},\mathbf{R}) =
  \sum_{\alpha=1}^{N_\text{nucl}} \sum_{i=1}^{N_\text{elec}} 
  \frac{a_{1,\alpha}\, g_\alpha(R_{i\alpha})}{1+a_{2,\alpha}\, g_\alpha(R_{i\alpha})} +
  \sum_{p=2}^{N_\text{ord}^a} a_{p+1,\alpha}\, [g_\alpha(R_{i\alpha})]^p - J_{eN}^{\infty \alpha}
  \]

  $J_{\text{ee}}$ contains electron-electron terms:
  \[
  J_{\text{ee}}(\mathbf{r}) =
  \sum_{i=1}^{N_\text{elec}} \sum_{j=1}^{i-1}
  \frac{b_1\, f(r_{ij})}{1+b_2\, f(r_{ij})} +
  \sum_{p=2}^{N_\text{ord}^b} a_{p+1}\, [f(r_{ij})]^p  - J_{ee}^\infty
  \]

  and $J_{\text{eeN}}$ contains electron-electron-Nucleus terms:

   \[
   J_{\text{eeN}}(\mathbf{r},\mathbf{R}) =
    \sum_{\alpha=1}^{N_{\text{nucl}}}
     \sum_{i=1}^{N_{\text{elec}}}
      \sum_{j=1}^{i-1}
       \sum_{p=2}^{N_{\text{ord}}}
        \sum_{k=0}^{p-1}
         \sum_{l=0}^{p-k-2\delta_{k,0}}
           c_{lkp\alpha} \left[ f({r}_{ij}) \right]^k
             \left[ \left[ g_\alpha({R}_{i\alpha}) \right]^l + \left[ g_\alpha({R}_{j\alpha}) \right]^l \right]
             \left[ g_\alpha({R}_{i\,\alpha}) \, g_\alpha({R}_{j\alpha}) \right]^{(p-k-l)/2}
   \]

  $c_{lkp\alpha}$ are non-zero only when $p-k-l$ is even.

  $f$ and $g$ are scaling function defined as

  \[
  f(r) = \frac{1-e^{-\kappa\, r}}{\kappa} \text{ and }
  g_\alpha(r) = e^{-\kappa_\alpha\, r}.
  \]

  The terms $J_{\text{ee}}^\infty$ and $J_{\text{eN}}^\infty$ are shifts to ensure that
  $J_{\text{ee}}$ and $J_{\text{eN}}$ have an asymptotic value of zero.

* Headers                                                          :noexport:
  #+begin_src elisp :noexport :results none
(org-babel-lob-ingest "../tools/lib.org")
#+end_src

  #+begin_src c :tangle (eval h_private_func)
#ifndef QMCKL_JASTROW_HPF
#define QMCKL_JASTROW_HPF
  #+end_src

  #+begin_src c :tangle (eval h_private_type)
#ifndef QMCKL_JASTROW_HPT
#define QMCKL_JASTROW_HPT
#include <stdbool.h>
  #+end_src

  #+begin_src c :tangle (eval c_test) :noweb yes
#include "qmckl.h"
#include <assert.h>
#include <math.h>
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include "n2.h"

int main() {
  qmckl_context context;
  context = qmckl_context_create();
  #+end_src

  #+begin_src c :tangle (eval c)
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_STDINT_H
#include <stdint.h>
#elif HAVE_INTTYPES_H
#include <inttypes.h>
#endif

#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <assert.h>
#include <math.h>


#include <stdio.h>

#include "qmckl.h"
#include "qmckl_context_private_type.h"
#include "qmckl_memory_private_type.h"
#include "qmckl_memory_private_func.h"
#include "qmckl_jastrow_private_func.h"
#include "qmckl_jastrow_private_type.h"

#ifdef HAVE_CUBLAS_OFFLOAD
#include "cublas_v2.h"
#endif


  #+end_src

* Context
   :PROPERTIES:
   :Name:     qmckl_jastrow
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

  The following data stored in the context:

  #+NAME: qmckl_jastrow_args
    | Variable                  | Type                                  | In/Out | Description                                                       |
    |---------------------------+---------------------------------------+--------+-------------------------------------------------------------------|
    | ~uninitialized~           | ~int32_t~                             | in     | Keeps bits set for uninitialized data                             |
    | ~rescale_factor_ee~       | ~double~                              | in     | The distance scaling factor                                       |
    | ~rescale_factor_en~       | ~double[type_nucl_num]~               | in     | The distance scaling factor                                       |
    | ~aord_num~                | ~int64_t~                             | in     | The number of a coeffecients                                      |
    | ~bord_num~                | ~int64_t~                             | in     | The number of b coeffecients                                      |
    | ~cord_num~                | ~int64_t~                             | in     | The number of c coeffecients                                      |
    | ~type_nucl_num~           | ~int64_t~                             | in     | Number of Nuclei types                                           |
    | ~type_nucl_vector~        | ~int64_t[nucl_num]~                   | in     | IDs of types of Nuclei                                            |
    | ~a_vector~                | ~double[aord_num + 1][type_nucl_num]~ | in     | a polynomial coefficients                                         |
    | ~b_vector~                | ~double[bord_num + 1]~                | in     | b polynomial coefficients                                         |
    | ~c_vector~                | ~double[cord_num][type_nucl_num]~     | in     | c polynomial coefficients                                         |
    | ~factor_ee~               | ~double[walker.num]~                  | out    | Jastrow factor: electron-electron part                            |
    | ~factor_ee_date~          | ~uint64_t~                            | out    | Jastrow factor: electron-electron part                            |
    | ~factor_en~               | ~double[walker.num]~                  | out    | Jastrow factor: electron-nucleus  part                            |
    | ~factor_en_date~          | ~uint64_t~                            | out    | Jastrow factor: electron-nucleus  part                            |
    | ~factor_een~              | ~double[walker.num]~                  | out    | Jastrow factor: electron-electron-nucleus  part                   |
    | ~factor_een_date~         | ~uint64_t~                            | out    | Jastrow factor: electron-electron-nucleus  part                   |
    | ~factor_ee_deriv_e~       | ~double[4][nelec][walker.num]~        | out    | Derivative of the Jastrow factor: electron-electron-nucleus  part |
    | ~factor_ee_deriv_e_date~  | ~uint64_t~                            | out    | Keep track of the date for the derivative                         |
    | ~factor_en_deriv_e~       | ~double[4][nelec][walker.num]~        | out    | Derivative of the Jastrow factor: electron-electron-nucleus  part |
    | ~factor_en_deriv_e_date~  | ~uint64_t~                            | out    | Keep track of the date for the en derivative                      |
    | ~factor_een_deriv_e~      | ~double[4][nelec][walker.num]~        | out    | Derivative of the Jastrow factor: electron-electron-nucleus  part |
    | ~factor_een_deriv_e_date~ | ~uint64_t~                            | out    | Keep track of the date for the een derivative                     |

  computed data:

    | Variable                            | Type                                                              | In/Out                                                                                                  |
    |-------------------------------------+-------------------------------------------------------------------+---------------------------------------------------------------------------------------------------------|
    | ~dim_c_vector~                      | ~int64_t~                                                         | Number of unique C coefficients                                                                         |
    | ~dim_c_vector_date~                 | ~uint64_t~                                                        | Number of unique C coefficients                                                                         |
    | ~asymp_jasa~                        | ~double[type_nucl_num]~                                          | Asymptotic component                                                                                    |
    | ~asymp_jasa_date~                   | ~uint64_t~                                                        | Ladt modification of the asymptotic component                                                           |
    | ~asymp_jasb~                        | ~double[2]~                                                       | Asymptotic component (up- or down-spin)                                                                 |
    | ~asymp_jasb_date~                   | ~uint64_t~                                                        | Ladt modification of the asymptotic component                                                           |
    | ~c_vector_full~                     | ~double[dim_c_vector][nucl_num]~                                  | vector of non-zero coefficients                                                                         |
    | ~c_vector_full_date~                | ~uint64_t~                                                        | Keep track of changes here                                                                              |
    | ~lkpm_combined_index~               | ~int64_t[4][dim_c_vector]~                                        | Transform l,k,p, and m into consecutive indices                                                         |
    | ~lkpm_combined_index_date~          | ~uint64_t~                                                        | Transform l,k,p, and m into consecutive indices                                                         |
    | ~tmp_c~                             | ~double[walker.num][cord_num][cord_num+1][nucl_num][elec_num]~    | vector of non-zero coefficients                                                                         |
    | ~dtmp_c~                            | ~double[walker.num][elec_num][4][nucl_num][cord_num+1][cord_num]~ | vector of non-zero coefficients                                                                         |
    | ~ee_distance_rescaled~              | ~double[walker.num][num][num]~                                    | Electron-electron rescaled distances                                                                    |
    | ~ee_distance_rescaled_date~         | ~uint64_t~                                                        | Last modification date of the electron-electron distances                                               |
    | ~ee_distance_rescaled_deriv_e~      | ~double[walker.num][4][num][num]~                                 | Electron-electron rescaled distances derivatives                                                        |
    | ~ee_distance_rescaled_deriv_e_date~ | ~uint64_t~                                                        | Last modification date of the electron-electron distance derivatives                                    |
    | ~en_distance_rescaled~              | ~double[walker.num][nucl_num][num]~                               | Electron-nucleus distances                                                                              |
    | ~en_distance_rescaled_date~         | ~uint64_t~                                                        | Last modification date of the electron-electron distances                                               |
    | ~en_distance_rescaled_deriv_e~      | ~double[walker.num][4][nucl_num][num]~                            | Electron-electron rescaled distances derivatives                                                        |
    | ~en_distance_rescaled_deriv_e_date~ | ~uint64_t~                                                        | Last modification date of the electron-electron distance derivatives                                    |
    | ~een_rescaled_n~                    | ~double[walker.num][cord_num+1][nucl_num][elec_num]~              | The electron-electron rescaled distances raised to the powers defined by cord                           |
    | ~een_rescaled_n_date~               | ~uint64_t~                                                        | Keep track of the date of creation                                                                      |
    | ~een_rescaled_e_deriv_e~            | ~double[walker.num][cord_num+1][elec_num][4][elec_num]~           | The electron-electron rescaled distances raised to the powers defined by cord derivatives wrt electrons |
    | ~een_rescaled_e_deriv_e_date~       | ~uint64_t~                                                        | Keep track of the date of creation                                                                      |
    | ~een_rescaled_n_deriv_e~            | ~double[walker.num][cord_num+1][nucl_num][4][elec_num]~           | The electron-electron rescaled distances raised to the powers defined by cord derivatives wrt electrons |
    | ~een_rescaled_n_deriv_e_date~       | ~uint64_t~                                                        | Keep track of the date of creation                                                                      |

   #+NAME: jastrow_data
   #+BEGIN_SRC python :results none :exports none
import numpy as np

# For H2O we have the following data:
elec_num     = 10
nucl_num     = 2
up_num       = 5
down_num     = 5
nucl_coord = np.array([ [0.000000,  0.000000 ],
   [0.000000,  0.000000 ],
   [0.000000,  2.059801 ] ])

elec_coord = np.array(   [[[-0.250655104764153      ,  0.503070975550133      ,  -0.166554344502303],
     [-0.587812193472177      , -0.128751981129274      ,   0.187773606533075],
     [ 1.61335569047166       , -0.615556732874863      ,  -1.43165470979934 ],
     [-4.901239896295210E-003 , -1.120440036458986E-002 ,   1.99761909330422 ],
     [ 0.766647499681200      , -0.293515395797937      ,   3.66454589201239 ],
     [-0.127732483187947      , -0.138975497694196      ,  -8.669850480215846E-002],
     [-0.232271834949124      , -1.059321673434182E-002 ,  -0.504862241464867],
     [ 1.09360863531826       , -2.036103063808752E-003 ,  -2.702796910818986E-002],
     [-0.108090166832043      ,  0.189161729653261      ,   2.15398313919894],
     [ 0.397978144318712      , -0.254277292595981      ,   2.54553335476344]]])

ee_distance_rescaled = np.array([
[ 0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.550227800352402, 0.000000000000000, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.919155060185168, 0.937695909123175, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.893325429242815, 0.851181978173561, 0.978501685226877,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.982457268305353, 0.976125002619471, 0.994349933143149,
  0.844077311588328, 0.000000000000000, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.482407528408731, 0.414816073699124, 0.894716035479343,
  0.876540187084407, 0.978921170036895, 0.000000000000000,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.459541909660400, 0.545007215761510, 0.883752955884551,
  0.918958134888791, 0.986386936267237, 0.362209822236419,
  0.000000000000000, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.763732576854455, 0.817282762358449, 0.801802919535959,
  0.900089095449775, 0.975704636491453, 0.707836537586060,
  0.755705808346586, 0.000000000000000, 0.000000000000000,
  0.000000000000000 ],
[ 0.904249454052971, 0.871097965261373, 0.982717262706270,
  0.239901207363622, 0.836519456769083, 0.896135326270534,
  0.930694340243023, 0.917708540815567, 0.000000000000000,
  0.000000000000000 ],
[ 0.944400908070716, 0.922589018494961, 0.984615718580670,
  0.514328661540623, 0.692362267147064, 0.931894098453677,
  0.956034127544344, 0.931221472309472, 0.540903688625053,
  0.000000000000000 ]])

en_distance_rescaled = np.transpose(np.array([
[ 0.443570948411811  ,    0.467602196999105    ,  0.893870160799932 ,
  0.864347190364447  ,    0.976608182392358    ,  0.187563183468210 ,
  0.426404699872689  ,    0.665107090128166    ,  0.885246991424583 ,
  0.924902909715270     ],
[ 0.899360150637444     , 0.860035135365386   ,   0.979659405613798 ,
  6.140678415933776E-002, 0.835118398056681   ,   0.884071658981068 ,
  0.923860000907362     , 0.905203414522289   ,   0.211286300932359 ,
  0.492104840907350 ]]))

# symmetrize it
for i in range(elec_num):
  for j in range(elec_num):
    ee_distance_rescaled[i][j] = ee_distance_rescaled[j][i]

# For N2, we have the following data:
type_nucl_num = 1
aord_num     = 5
bord_num     = 5
cord_num     = 5
dim_c_vector= 23
type_nucl_vector = [ 1, 1]
a_vector = np.array([
[0.000000000000000E+000],
[0.000000000000000E+000],
[-0.380512000000000E+000],
[-0.157996000000000E+000],
[-3.155800000000000E-002],
[2.151200000000000E-002]])

b_vector =np.array( [ 0.500000000000000E-000,  0.153660000000000E-000,  6.722620000000000E-002,
  2.157000000000000E-002,  7.309600000000000E-003,  2.866000000000000E-003])
c_vector = [ 0.571702000000000E-000, -0.514253000000000E-000, -0.513043000000000E-000,
  9.486000000000000E-003, -4.205000000000000E-003,  0.426325800000000E-000,
  8.288150000000000E-002,  5.118600000000000E-003, -2.997800000000000E-003,
 -5.270400000000000E-003, -7.499999999999999E-005, -8.301649999999999E-002,
  1.454340000000000E-002,  5.143510000000000E-002,  9.250000000000000E-004,
 -4.099100000000000E-003,  4.327600000000000E-003, -1.654470000000000E-003,
  2.614000000000000E-003, -1.477000000000000E-003, -1.137000000000000E-003,
 -4.010475000000000E-002,  6.106710000000000E-003 ]
c_vector_full = [
[ 0.571702000000000E-000, -0.514253000000000E-000, -0.513043000000000E-000,
  9.486000000000000E-003, -4.205000000000000E-003,  0.426325800000000E-000,
  8.288150000000000E-002,  5.118600000000000E-003, -2.997800000000000E-003,
 -5.270400000000000E-003, -7.499999999999999E-005, -8.301649999999999E-002,
  1.454340000000000E-002,  5.143510000000000E-002,  9.250000000000000E-004,
 -4.099100000000000E-003,  4.327600000000000E-003, -1.654470000000000E-003,
  2.614000000000000E-003, -1.477000000000000E-003, -1.137000000000000E-003,
 -4.010475000000000E-002,  6.106710000000000E-003 ],
[ 0.571702000000000E-000, -0.514253000000000E-000, -0.513043000000000E-000,
  9.486000000000000E-003, -4.205000000000000E-003,  0.426325800000000E-000,
  8.288150000000000E-002,  5.118600000000000E-003, -2.997800000000000E-003,
 -5.270400000000000E-003, -7.499999999999999E-005, -8.301649999999999E-002,
  1.454340000000000E-002,  5.143510000000000E-002,  9.250000000000000E-004,
 -4.099100000000000E-003,  4.327600000000000E-003, -1.654470000000000E-003,
  2.614000000000000E-003, -1.477000000000000E-003, -1.137000000000000E-003,
 -4.010475000000000E-002,  6.106710000000000E-003 ],
]
lkpm_combined_index = [[1 , 1 , 2 , 0],
          [0 , 0 , 2 , 1],
          [1 , 2 , 3 , 0],
          [2 , 1 , 3 , 0],
          [0 , 1 , 3 , 1],
          [1 , 0 , 3 , 1],
          [1 , 3 , 4 , 0],
          [2 , 2 , 4 , 0],
          [0 , 2 , 4 , 1],
          [3 , 1 , 4 , 0],
          [1 , 1 , 4 , 1],
          [2 , 0 , 4 , 1],
          [0 , 0 , 4 , 2],
          [1 , 4 , 5 , 0],
          [2 , 3 , 5 , 0],
          [0 , 3 , 5 , 1],
          [3 , 2 , 5 , 0],
          [1 , 2 , 5 , 1],
          [4 , 1 , 5 , 0],
          [2 , 1 , 5 , 1],
          [0 , 1 , 5 , 2],
          [3 , 0 , 5 , 1],
          [1 , 0 , 5 , 2]]

kappa     = 1.0
kappa_inv = 1.0/kappa
   #+END_SRC

** Data structure

   #+begin_src c :comments org :tangle (eval h_private_type)
typedef struct qmckl_jastrow_struct{
  int32_t   uninitialized;
  int64_t   aord_num;
  int64_t   bord_num;
  int64_t   cord_num;
  int64_t   type_nucl_num;
  uint64_t  asymp_jasa_date;
  uint64_t  asymp_jasb_date;
  uint64_t  tmp_c_date;
  uint64_t  dtmp_c_date;
  uint64_t  factor_ee_date;
  uint64_t  factor_en_date;
  uint64_t  factor_een_date;
  uint64_t  factor_ee_deriv_e_date;
  uint64_t  factor_en_deriv_e_date;
  uint64_t  factor_een_deriv_e_date;
  double    rescale_factor_ee;
  double*   rescale_factor_en;
  int64_t*  type_nucl_vector;
  double *  a_vector;
  double *  b_vector;
  double *  c_vector;
  double *  asymp_jasa;
  double *  asymp_jasb;
  double *  factor_ee;
  double *  factor_en;
  double *  factor_een;
  double *  factor_ee_deriv_e;
  double *  factor_en_deriv_e;
  double *  factor_een_deriv_e;
  int64_t   dim_c_vector;
  uint64_t  dim_c_vector_date;
  double *  c_vector_full;
  uint64_t  c_vector_full_date;
  int64_t*  lkpm_combined_index;
  uint64_t  lkpm_combined_index_date;
  double *  tmp_c;
  double *  dtmp_c;
  uint64_t  ee_distance_rescaled_date;
  uint64_t  ee_distance_rescaled_deriv_e_date;
  uint64_t  en_distance_rescaled_date;
  uint64_t  en_distance_rescaled_deriv_e_date;
  double*   ee_distance_rescaled;
  double*   ee_distance_rescaled_deriv_e;
  double*   en_distance_rescaled;
  double*   en_distance_rescaled_deriv_e;
  double *  een_rescaled_e;
  double *  een_rescaled_n;
  uint64_t  een_rescaled_e_date;
  uint64_t  een_rescaled_n_date;
  double *  een_rescaled_e_deriv_e;
  double *  een_rescaled_n_deriv_e;
  uint64_t  een_rescaled_e_deriv_e_date;
  uint64_t  een_rescaled_n_deriv_e_date;
  bool      provided;
  char *    type;

  #ifdef HAVE_HPC
  bool     gpu_offload;
  #endif
} qmckl_jastrow_struct;
    #+end_src


   The ~uninitialized~ integer contains one bit set to one for each
   initialization function which has not been called. It becomes equal
   to zero after all initialization functions have been called. The
   struct is then initialized and ~provided == true~.
   Some values are initialized by default, and are not concerned by
   this mechanism.

   #+begin_src c :comments org :tangle (eval h_func)
qmckl_exit_code qmckl_init_jastrow(qmckl_context context);
   #+end_src

   #+begin_src c :comments org :tangle (eval c)
qmckl_exit_code qmckl_init_jastrow(qmckl_context context) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return false;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  ctx->jastrow.uninitialized = (1 << 10) - 1;

  /* Default values */
  ctx->jastrow.aord_num = -1;
  ctx->jastrow.bord_num = -1;
  ctx->jastrow.cord_num = -1;
  ctx->jastrow.type_nucl_num = -1;
  ctx->jastrow.dim_c_vector = -1;

  return QMCKL_SUCCESS;
}
   #+end_src

** Initialization functions

   To prepare for the Jastrow and its derivative, all the following functions need to be
   called.

   #+begin_src c :comments org :tangle (eval h_func)
qmckl_exit_code  qmckl_set_jastrow_rescale_factor_ee (qmckl_context context, const double  kappa_ee);
qmckl_exit_code  qmckl_set_jastrow_rescale_factor_en (qmckl_context context, const double* kappa_en, const int64_t size_max);
qmckl_exit_code  qmckl_set_jastrow_aord_num          (qmckl_context context, const int64_t aord_num);
qmckl_exit_code  qmckl_set_jastrow_bord_num          (qmckl_context context, const int64_t bord_num);
qmckl_exit_code  qmckl_set_jastrow_cord_num          (qmckl_context context, const int64_t cord_num);
qmckl_exit_code  qmckl_set_jastrow_type_nucl_num     (qmckl_context context, const int64_t type_nucl_num);
qmckl_exit_code  qmckl_set_jastrow_type_nucl_vector  (qmckl_context context, const int64_t* type_nucl_vector, const int64_t nucl_num);
qmckl_exit_code  qmckl_set_jastrow_a_vector       (qmckl_context context, const double * a_vector, const int64_t size_max);
qmckl_exit_code  qmckl_set_jastrow_b_vector       (qmckl_context context, const double * b_vector, const int64_t size_max);
qmckl_exit_code  qmckl_set_jastrow_c_vector       (qmckl_context context, const double * c_vector, const int64_t size_max);
   #+end_src

   #+NAME:pre2
   #+begin_src c  :exports none
if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
  return QMCKL_NULL_CONTEXT;
 }

qmckl_context_struct* const ctx = (qmckl_context_struct*) context;

if (mask != 0 && !(ctx->jastrow.uninitialized & mask)) {
  printf("%d %d\n", mask, ctx->jastrow.uninitialized );
    return qmckl_failwith( context,
                           QMCKL_ALREADY_SET,
                           "qmckl_set_jastrow_*",
                           NULL);
 }
   #+end_src

   #+NAME:post2
   #+begin_src c  :exports none
ctx->jastrow.uninitialized &= ~mask;
ctx->jastrow.provided = (ctx->jastrow.uninitialized == 0);
if (ctx->jastrow.provided) {
  qmckl_exit_code rc_ = qmckl_finalize_jastrow(context);
  if (rc_ != QMCKL_SUCCESS) return rc_;
 }

return QMCKL_SUCCESS;
   #+end_src


   #+begin_src c :comments org :tangle (eval c) :noweb yes :exports none
qmckl_exit_code
qmckl_set_jastrow_aord_num(qmckl_context context, const int64_t aord_num)
{

  int32_t mask = 1 << 0;

<<pre2>>

  if (aord_num < 0) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_aord_num",
                           "aord_num < 0");
  }

  ctx->jastrow.aord_num = aord_num;

  <<post2>>
}

qmckl_exit_code
qmckl_set_jastrow_bord_num(qmckl_context context, const int64_t bord_num)
{

  int32_t mask = 1 << 1;

<<pre2>>

  if (bord_num < 0) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_bord_num",
                           "bord_num < 0");
  }

  ctx->jastrow.bord_num = bord_num;

  <<post2>>
}

qmckl_exit_code
qmckl_set_jastrow_cord_num(qmckl_context context, const int64_t cord_num)
{

  int32_t mask = 1 << 2;

<<pre2>>

  if (cord_num < 0) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_cord_num",
                           "cord_num < 0");
  }

  int64_t dim_c_vector = -1;
  qmckl_exit_code rc = qmckl_compute_dim_c_vector(context, cord_num, &dim_c_vector);
  assert (rc == QMCKL_SUCCESS);

  ctx->jastrow.cord_num = cord_num;
  ctx->jastrow.dim_c_vector = dim_c_vector;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_type_nucl_num(qmckl_context context, const int64_t type_nucl_num)
{
  int32_t mask = 1 << 3;

<<pre2>>

  if (type_nucl_num <= 0) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_type_nucl_num",
                           "type_nucl_num < 0");
  }

  ctx->jastrow.type_nucl_num = type_nucl_num;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_type_nucl_vector(qmckl_context context,
                                   int64_t const * type_nucl_vector,
                                   const int64_t nucl_num)
{

  int32_t mask = 1 << 4;

<<pre2>>

  int64_t type_nucl_num = ctx->jastrow.type_nucl_num;

  if (type_nucl_num <= 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_set_jastrow_type_nucl_vector",
                           "type_nucl_num not initialized");
  }

  if (type_nucl_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_type_nucl_vector",
                           "type_nucl_vector = NULL");
  }

  if (ctx->jastrow.type_nucl_vector != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.type_nucl_vector);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_type_nucl_vector",
                             "Unable to free ctx->jastrow.type_nucl_vector");
    }
  }

  qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
  mem_info.size = nucl_num * sizeof(int64_t);
  int64_t* new_array = (int64_t*) qmckl_malloc(context, mem_info);

  if(new_array == NULL) {
    return qmckl_failwith( context,
                           QMCKL_ALLOCATION_FAILED,
                           "qmckl_set_jastrow_type_nucl_vector",
                           NULL);
  }

  memcpy(new_array, type_nucl_vector, mem_info.size);

  ctx->jastrow.type_nucl_vector = new_array;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_a_vector(qmckl_context context,
                              double const * a_vector,
                              const int64_t size_max)
{
  int32_t mask = 1 << 5;

<<pre2>>

  int64_t aord_num = ctx->jastrow.aord_num;
  if (aord_num < 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_set_jastrow_a_vector",
                           "aord_num not initialized");
  }
    
  int64_t type_nucl_num = ctx->jastrow.type_nucl_num;

  if (type_nucl_num <= 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_set_jastrow_a_vector",
                           "type_nucl_num not initialized");
  }

  if (a_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_a_vector",
                           "a_vector = NULL");
  }

  if (ctx->jastrow.a_vector != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.a_vector);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_jastrow_a_vector",
                             "Unable to free ctx->jastrow.a_vector");
    }
  }

  qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
  mem_info.size = (aord_num + 1) * type_nucl_num * sizeof(double);

  if (size_max < (aord_num+1)*type_nucl_num ) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_set_jastrow_a_vector",
                           "Array too small. Expected (aord_num+1)*type_nucl_num");
  }

  double* new_array = (double*) qmckl_malloc(context, mem_info);

  if(new_array == NULL) {
    return qmckl_failwith( context,
                           QMCKL_ALLOCATION_FAILED,
                           "qmckl_set_jastrow_coefficient",
                           NULL);
  }

  memcpy(new_array, a_vector, mem_info.size);

  ctx->jastrow.a_vector = new_array;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_b_vector(qmckl_context context,
                              double const * b_vector,
                              const int64_t size_max)
{
  int32_t mask = 1 << 6;

<<pre2>>

    int64_t bord_num = ctx->jastrow.bord_num;
  if (bord_num < 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_set_jastrow_b_vector",
                           "bord_num not initialized");
  }

  if (b_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_b_vector",
                           "b_vector = NULL");
  }

  if (ctx->jastrow.b_vector != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.b_vector);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_jastrow_b_vector",
                             "Unable to free ctx->jastrow.b_vector");
    }
  }

  qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
  mem_info.size = (bord_num + 1) * sizeof(double);

  if (size_max < (bord_num+1)) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_set_jastrow_b_vector",
                           "Array too small. Expected (bord_num+1)");
  }

  double* new_array = (double*) qmckl_malloc(context, mem_info);

  if(new_array == NULL) {
    return qmckl_failwith( context,
                           QMCKL_ALLOCATION_FAILED,
                           "qmckl_set_jastrow_coefficient",
                           NULL);
  }

  memcpy(new_array, b_vector, mem_info.size);

  ctx->jastrow.b_vector = new_array;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_c_vector(qmckl_context context,
                              double const * c_vector,
                              const int64_t size_max)
{
  int32_t mask = 1 << 7;

<<pre2>>

  int64_t type_nucl_num = ctx->jastrow.type_nucl_num;
  if (type_nucl_num <= 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_set_jastrow_c_vector",
                           "type_nucl_num not initialized");
  }

  int64_t dim_c_vector = ctx->jastrow.dim_c_vector;
  if (dim_c_vector < 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_set_jastrow_c_vector",
                           "cord_num not initialized");
  }

  if (c_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_c_vector",
                           "c_vector = NULL");
  }

  if (ctx->jastrow.c_vector != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.c_vector);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_jastrow_c_vector",
                             "Unable to free ctx->jastrow.c_vector");
    }
  }

  qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
  mem_info.size = dim_c_vector * type_nucl_num * sizeof(double);

  if ((size_t) size_max < mem_info.size/sizeof(double)) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_set_jastrow_c_vector",
                           "Array too small. Expected dim_c_vector * type_nucl_num");
  }

  double* new_array = (double*) qmckl_malloc(context, mem_info);

  if(new_array == NULL) {
    return qmckl_failwith( context,
                           QMCKL_ALLOCATION_FAILED,
                           "qmckl_set_jastrow_coefficient",
                           NULL);
  }

  memcpy(new_array, c_vector, mem_info.size);

  ctx->jastrow.c_vector = new_array;

  <<post2>>
}

qmckl_exit_code
qmckl_set_jastrow_rescale_factor_ee(qmckl_context context,
                const double rescale_factor_ee) {

  int32_t mask = 1 << 8;
  
  <<pre2>>

  if (rescale_factor_ee <= 0.0) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_rescale_factor_ee",
                           "rescale_factor_ee <= 0.0");
  }

  ctx->jastrow.rescale_factor_ee = rescale_factor_ee;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_rescale_factor_en(qmckl_context context,
                                     const double* rescale_factor_en,
                                     const int64_t size_max) {

  int32_t mask = 1 << 9;

  <<pre2>>

      if (ctx->jastrow.type_nucl_num <= 0) {
        return qmckl_failwith( context,
                               QMCKL_NOT_PROVIDED,
                               "qmckl_set_jastrow_rescale_factor_en",
                               "type_nucl_num not set");
      }


      if (rescale_factor_en == NULL) {
        return qmckl_failwith( context,
                               QMCKL_INVALID_ARG_2,
                               "qmckl_set_jastrow_rescale_factor_en",
                               "Null pointer");
      }

      if (size_max < ctx->jastrow.type_nucl_num) {
        return qmckl_failwith( context,
                               QMCKL_INVALID_ARG_3,
                               "qmckl_set_jastrow_rescale_factor_en",
                               "Array too small");
      }


      if (ctx->jastrow.rescale_factor_en != NULL) {
        return qmckl_failwith( context,
                               QMCKL_INVALID_ARG_3,
                               "qmckl_set_jastrow_rescale_factor_en",
                               "Already set");
      }

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->jastrow.type_nucl_num * sizeof(double);
      ctx->jastrow.rescale_factor_en = (double*) qmckl_malloc(context, mem_info);

      for (int64_t i=0 ; i<ctx->jastrow.type_nucl_num ; ++i) {
        if (rescale_factor_en[i] <= 0.0) {
          return qmckl_failwith( context,
                                 QMCKL_INVALID_ARG_2,
                                 "qmckl_set_jastrow_rescale_factor_en",
                                 "rescale_factor_en <= 0.0");
        }
        ctx->jastrow.rescale_factor_en[i] = rescale_factor_en[i];
      }

  <<post2>>
}
   #+end_src

 When the required information is completely entered, other data structures are
 computed to accelerate the calculations. The intermediates factors
 are precontracted using BLAS LEVEL 3 operations for an optimal flop count.

   #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_finalize_jastrow(qmckl_context context);
   #+end_src

   #+begin_src c :comments org :tangle (eval c) :noweb yes :exports none
qmckl_exit_code qmckl_finalize_jastrow(qmckl_context context) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* ----------------------------------- */
  /* Check for the necessary information */
  /* ----------------------------------- */

  /* Check for the electron data
     1. elec_num
     2. ee_distances_rescaled
  ,*/
  if (!(ctx->electron.provided)) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_electron",
                           NULL);
  }

  /* Check for the nucleus data
     1. nucl_num
     2. en_distances_rescaled
  ,*/
  if (!(ctx->nucleus.provided)) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_nucleus",
                           NULL);
  }

  /* Decide if the Jastrow if offloaded on GPU or not */
#if defined(HAVE_HPC) && (defined(HAVE_CUBLAS_OFFLOAD) || defined(HAVE_OPENACC_OFFLOAD) || defined(HAVE_OPENMP_OFFLOAD))
  ctx->jastrow.gpu_offload = true; // ctx->electron.num > 100;
#endif

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_asymp_jasa(context);
  assert(rc == QMCKL_SUCCESS);

  rc = qmckl_provide_jastrow_asymp_jasb(context);
  assert(rc == QMCKL_SUCCESS);

  rc = qmckl_context_touch(context);
  return rc;


}
   #+end_src

**** Fortran interface

#+begin_src f90 :tangle (eval fh_func) :comments org
interface
   integer(qmckl_exit_code) function qmckl_set_jastrow_rescale_factor_ee (context, &
        kappa_ee) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     double precision, intent(in), value  :: kappa_ee
   end function qmckl_set_jastrow_rescale_factor_ee

   integer(qmckl_exit_code) function qmckl_set_jastrow_rescale_factor_en (context, &
        kappa_en, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: size_max
     double precision, intent(in) :: kappa_en(size_max)
   end function qmckl_set_jastrow_rescale_factor_en
   
   integer(qmckl_exit_code) function qmckl_set_jastrow_aord_num (context, &
        aord_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: aord_num
   end function qmckl_set_jastrow_aord_num
   
   integer(qmckl_exit_code) function qmckl_set_jastrow_bord_num (context, &
        bord_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: bord_num
   end function qmckl_set_jastrow_bord_num
   
   integer(qmckl_exit_code) function qmckl_set_jastrow_cord_num (context, &
        cord_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: cord_num
   end function qmckl_set_jastrow_cord_num

   integer(qmckl_exit_code) function qmckl_set_jastrow_type_nucl_num (context, &
        type_nucl_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: type_nucl_num
   end function qmckl_set_jastrow_type_nucl_num
   
   integer(qmckl_exit_code) function qmckl_set_jastrow_type_nucl_vector (context, &
        type_nucl_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: size_max
     integer(c_int64_t), intent(in) :: type_nucl_vector(size_max)
   end function qmckl_set_jastrow_type_nucl_vector
   
   integer(qmckl_exit_code) function qmckl_set_jastrow_a_vector(context, &
        a_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: size_max
     double precision, intent(in) :: a_vector(size_max)
   end function qmckl_set_jastrow_a_vector
   
   integer(qmckl_exit_code) function qmckl_set_jastrow_b_vector(context, &
        b_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: size_max
     double precision, intent(in) :: b_vector(size_max)
   end function qmckl_set_jastrow_b_vector
   
   integer(qmckl_exit_code) function qmckl_set_jastrow_c_vector(context, &
        c_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value  :: size_max
     double precision, intent(in) :: c_vector(size_max)
   end function qmckl_set_jastrow_c_vector
   
end interface
#+end_src

** Access functions

   #+begin_src c :comments org :tangle (eval h_func) :exports none
qmckl_exit_code  qmckl_get_jastrow_aord_num          (qmckl_context context, int64_t* const aord_num);
qmckl_exit_code  qmckl_get_jastrow_bord_num          (qmckl_context context, int64_t* const bord_num);
qmckl_exit_code  qmckl_get_jastrow_cord_num          (qmckl_context context, int64_t* const bord_num);
qmckl_exit_code  qmckl_get_jastrow_type_nucl_num     (qmckl_context context, int64_t* const type_nucl_num);
qmckl_exit_code  qmckl_get_jastrow_type_nucl_vector  (qmckl_context context, int64_t* const type_nucl_num, const int64_t size_max);
qmckl_exit_code  qmckl_get_jastrow_a_vector          (qmckl_context context, double * const a_vector, const int64_t size_max);
qmckl_exit_code  qmckl_get_jastrow_b_vector          (qmckl_context context, double * const b_vector, const int64_t size_max);
qmckl_exit_code  qmckl_get_jastrow_c_vector          (qmckl_context context, double * const c_vector, const int64_t size_max);
qmckl_exit_code  qmckl_get_jastrow_rescale_factor_ee (const qmckl_context context, double* const rescale_factor_ee);
qmckl_exit_code  qmckl_get_jastrow_rescale_factor_en (const qmckl_context context, double* const rescale_factor_en, const int64_t size_max);
      #+end_src

      
   Along with these core functions, calculation of the jastrow factor
   requires the following additional information to be set:


   When all the data for the AOs have been provided, the following
   function returns ~true~.

   #+begin_src c :comments org :tangle (eval h_func)
bool      qmckl_jastrow_provided           (const qmckl_context context);
   #+end_src

      #+begin_src c :comments org :tangle (eval c) :noweb yes :exports none
bool qmckl_jastrow_provided(const qmckl_context context) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return false;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  return ctx->jastrow.provided;
}
      #+end_src

   #+begin_src c :comments org :tangle (eval c) :noweb yes :exports none
qmckl_exit_code qmckl_get_jastrow_aord_num (const qmckl_context context, int64_t* const aord_num) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (aord_num == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_aord_num",
                           "aord_num is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 0;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.aord_num > 0);
  ,*aord_num = ctx->jastrow.aord_num;
  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_bord_num (const qmckl_context context, int64_t* const bord_num) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (bord_num == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_bord_num",
                           "aord_num is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 1;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.bord_num > 0);
  ,*bord_num = ctx->jastrow.bord_num;
  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_cord_num (const qmckl_context context, int64_t* const cord_num) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (cord_num == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_cord_num",
                           "aord_num is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 2;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.cord_num > 0);
  ,*cord_num = ctx->jastrow.cord_num;
  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_type_nucl_num (const qmckl_context context, int64_t* const type_nucl_num) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (type_nucl_num == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_type_nucl_num",
                           "type_nucl_num is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 3;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.type_nucl_num > 0);
  ,*type_nucl_num = ctx->jastrow.type_nucl_num;
  return QMCKL_SUCCESS;
}

qmckl_exit_code
qmckl_get_jastrow_type_nucl_vector (const qmckl_context context,
                                    int64_t* const type_nucl_vector,
                                    const int64_t size_max)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (type_nucl_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_type_nucl_vector",
                           "type_nucl_vector is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 4;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.type_nucl_vector != NULL);
  if (size_max < ctx->jastrow.type_nucl_num) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_type_nucl_vector",
                           "Array too small. Expected jastrow.type_nucl_num");
  }

  memcpy(type_nucl_vector, ctx->jastrow.type_nucl_vector, ctx->jastrow.type_nucl_num*sizeof(int64_t));
  return QMCKL_SUCCESS;
}

qmckl_exit_code
qmckl_get_jastrow_a_vector (const qmckl_context context,
                               double * const a_vector,
                               const int64_t size_max) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (a_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_a_vector",
                           "a_vector is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 5;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.a_vector != NULL);
  int64_t sze = (ctx->jastrow.aord_num + 1)*ctx->jastrow.type_nucl_num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_a_vector",
                           "Array too small. Expected (ctx->jastrow.aord_num + 1)*ctx->jastrow.type_nucl_num");
  }
  memcpy(a_vector, ctx->jastrow.a_vector, sze*sizeof(double));
  return QMCKL_SUCCESS;
}

qmckl_exit_code
qmckl_get_jastrow_b_vector (const qmckl_context context,
                               double * const b_vector,
                               const int64_t size_max) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (b_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_b_vector",
                           "b_vector is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 6;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.b_vector != NULL);
  int64_t sze=ctx->jastrow.bord_num +1;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_b_vector",
                           "Array too small. Expected (ctx->jastrow.bord_num + 1)");
  }
  memcpy(b_vector, ctx->jastrow.b_vector, sze*sizeof(double));
  return QMCKL_SUCCESS;
}

qmckl_exit_code
qmckl_get_jastrow_c_vector (const qmckl_context context,
                               double * const c_vector,
                               const int64_t size_max) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return (char) 0;
  }

  if (c_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_c_vector",
                           "c_vector is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 7;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  assert (ctx->jastrow.c_vector != NULL);

  int64_t dim_c_vector;
  qmckl_exit_code rc = qmckl_get_jastrow_dim_c_vector(context, &dim_c_vector);
  if (rc != QMCKL_SUCCESS) return rc;

  int64_t sze=dim_c_vector * ctx->jastrow.type_nucl_num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_c_vector",
                           "Array too small. Expected dim_c_vector * jastrow.type_nucl_num");
  }
  memcpy(c_vector, ctx->jastrow.c_vector, sze*sizeof(double));
  return QMCKL_SUCCESS;
}

qmckl_exit_code
qmckl_get_jastrow_rescale_factor_ee (const qmckl_context context,
                                      double* const rescale_factor_ee) {

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (rescale_factor_ee == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_rescale_factor_ee",
                           "rescale_factor_ee is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 8;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }
  assert (ctx->jastrow.rescale_factor_ee > 0.0);

  ,*rescale_factor_ee = ctx->jastrow.rescale_factor_ee;
  return QMCKL_SUCCESS;
}


qmckl_exit_code
qmckl_get_jastrow_rescale_factor_en (const qmckl_context context,
                                      double* const rescale_factor_en,
                                      const int64_t size_max) {
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (rescale_factor_en == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_jastrow_rescale_factor_en",
                           "rescale_factor_en is a null pointer");
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 9;

  if ( (ctx->jastrow.uninitialized & mask) != 0) {
    return QMCKL_NOT_PROVIDED;
  }

  if (size_max < ctx->jastrow.type_nucl_num) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_rescale_factor_en",
                           "Array to small");
  }

  assert(ctx->jastrow.rescale_factor_en != NULL);
  for (int64_t i=0 ; i<ctx->jastrow.type_nucl_num ; ++i) {
    rescale_factor_en[i] = ctx->jastrow.rescale_factor_en[i];
  }

  return QMCKL_SUCCESS;
}
      #+end_src

**** Fortran interface

#+begin_src f90 :tangle (eval fh_func) :comments org
interface
   integer(qmckl_exit_code) function qmckl_get_jastrow_rescale_factor_ee (context, &
        kappa_ee) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     double precision, intent(out) :: kappa_ee
   end function qmckl_get_jastrow_rescale_factor_ee

   integer(qmckl_exit_code) function qmckl_get_jastrow_rescale_factor_en (context, &
        kappa_en, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(in), value       :: size_max
     double precision, intent(out)               :: kappa_en(size_max)
   end function qmckl_get_jastrow_rescale_factor_en
   
   integer(qmckl_exit_code) function qmckl_get_jastrow_aord_num (context, &
        aord_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(out)             :: aord_num
   end function qmckl_get_jastrow_aord_num
   
   integer(qmckl_exit_code) function qmckl_get_jastrow_bord_num (context, &
        bord_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(out)             :: bord_num
   end function qmckl_get_jastrow_bord_num
   
   integer(qmckl_exit_code) function qmckl_get_jastrow_cord_num (context, &
        cord_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(out)             :: cord_num
   end function qmckl_get_jastrow_cord_num

   integer(qmckl_exit_code) function qmckl_get_jastrow_type_nucl_num (context, &
        type_nucl_num) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(out)              :: type_nucl_num
   end function qmckl_get_jastrow_type_nucl_num
   
   integer(qmckl_exit_code) function qmckl_get_jastrow_type_nucl_vector (context, &
        type_nucl_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context), intent(in), value :: context
     integer(c_int64_t), intent(in), value      :: size_max
     integer(c_int64_t), intent(out)            :: type_nucl_vector(size_max)
   end function qmckl_get_jastrow_type_nucl_vector
   
   integer(qmckl_exit_code) function qmckl_get_jastrow_a_vector(context, &
        a_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(in), value       :: size_max
     double precision, intent(out)               :: a_vector(size_max)
   end function qmckl_get_jastrow_a_vector
   
   integer(qmckl_exit_code) function qmckl_get_jastrow_b_vector(context, &
        b_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value         :: size_max
     double precision, intent(out)                 :: b_vector(size_max)
   end function qmckl_get_jastrow_b_vector
   
   integer(qmckl_exit_code) function qmckl_get_jastrow_c_vector(context, &
        c_vector, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in)  , value :: context
     integer(c_int64_t), intent(in), value         :: size_max
     double precision, intent(out)                 :: c_vector(size_max)
   end function qmckl_get_jastrow_c_vector
   
end interface
#+end_src

** Test
   #+begin_src c :tangle (eval c_test)
/* Reference input data */
int64_t walk_num      = n2_walk_num;
int64_t elec_num      = n2_elec_num;
int64_t elec_up_num   = n2_elec_up_num;
int64_t elec_dn_num   = n2_elec_dn_num;
int64_t nucl_num      = n2_nucl_num;
double  rescale_factor_ee   = 1.0;
double  rescale_factor_en[2] = { 1.0, 1.0 };
double* elec_coord    = &(n2_elec_coord[0][0][0]);

const double*   nucl_charge   = n2_charge;
double*  nucl_coord    = &(n2_nucl_coord[0][0]);
int64_t size_max;

/* Provide Electron data */

qmckl_exit_code rc;

assert(!qmckl_electron_provided(context));

rc = qmckl_check(context,
                 qmckl_set_electron_num (context, elec_up_num, elec_dn_num)
                 );
assert(rc == QMCKL_SUCCESS);

assert(qmckl_electron_provided(context));

rc = qmckl_check(context,
                 qmckl_set_electron_coord (context, 'N', walk_num, elec_coord, walk_num*3*elec_num)
                 );
assert(rc == QMCKL_SUCCESS);

double elec_coord2[walk_num*3*elec_num];

rc = qmckl_check(context,
                 qmckl_get_electron_coord (context, 'N', elec_coord2, walk_num*3*elec_num)
                 );
assert(rc == QMCKL_SUCCESS);
for (int64_t i=0 ; i<3*elec_num ; ++i) {
  assert( elec_coord[i] == elec_coord2[i] );
 }


/* Provide Nucleus data */

assert(!qmckl_nucleus_provided(context));

rc = qmckl_check(context,
                 qmckl_set_nucleus_num (context, nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_nucleus_provided(context));

double nucl_coord2[3*nucl_num];

rc = qmckl_get_nucleus_coord (context, 'T', nucl_coord2, 3*nucl_num);
assert(rc == QMCKL_NOT_PROVIDED);

rc = qmckl_check(context,
                 qmckl_set_nucleus_coord (context, 'T', &(nucl_coord[0]), 3*nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);

assert(!qmckl_nucleus_provided(context));

rc = qmckl_check(context,
                 qmckl_get_nucleus_coord (context, 'N', nucl_coord2, nucl_num*3)
                 );
assert(rc == QMCKL_SUCCESS);
for (int64_t k=0 ; k<3 ; ++k) {
  for (int64_t i=0 ; i<nucl_num ; ++i) {
    assert( nucl_coord[nucl_num*k+i] == nucl_coord2[3*i+k] );
  }
}

rc = qmckl_check(context,
                 qmckl_get_nucleus_coord (context, 'T', nucl_coord2, nucl_num*3)
                 );
assert(rc == QMCKL_SUCCESS);
for (int64_t i=0 ; i<3*nucl_num ; ++i) {
  assert( nucl_coord[i] == nucl_coord2[i] );
}

double nucl_charge2[nucl_num];

rc = qmckl_get_nucleus_charge(context, nucl_charge2, nucl_num);
assert(rc == QMCKL_NOT_PROVIDED);

rc = qmckl_check(context,
                 qmckl_set_nucleus_charge(context, nucl_charge, nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);

rc = qmckl_check(context,
                 qmckl_get_nucleus_charge(context, nucl_charge2, nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);
for (int64_t i=0 ; i<nucl_num ; ++i) {
  assert( nucl_charge[i] == nucl_charge2[i] );
 }
assert(qmckl_nucleus_provided(context));

    #+end_src

* Computation

  The computed data is stored in the context so that it can be reused
  by different kernels. To ensure that the data is valid, for each
  computed data the date of the context is stored when it is computed.
  To know if some data needs to be recomputed, we check if the date of
  the dependencies are more recent than the date of the data to
  compute. If it is the case, then the data is recomputed and the
  current date is stored.

** Asymptotic component for \(J_{ee}\)

  Calculate the asymptotic component ~asymp_jasb~ to be substracted from the final
  electron-electron jastrow factor \(J_{\text{ee}}\). The asymptotic component is calculated
  via the ~b_vector~ and the electron-electron rescale factor ~rescale_factor_ee~.

  \[
  J_{\text{ee}}^{\infty} = \frac{b_1 \kappa^{-1}}{1 + b_2  \kappa^{-1}}
  \]

*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_asymp_jasb(qmckl_context context,
                             double* const asymp_jasb,
                             const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_asymp_jasb(qmckl_context context,
                             double* const asymp_jasb,
                             const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_get_jastrow_asymp_jasb",
                           NULL);
  }


  /* Provided in finalize_jastrow */
  /*
  qmckl_exit_code rc;
  rc = qmckl_provide_jastrow_asymp_jasb(context);
  if(rc != QMCKL_SUCCESS) return rc;
  */

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = 2;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_asymp_jasb",
                           "Array too small. Expected 2");
  }
  memcpy(asymp_jasb, ctx->jastrow.asymp_jasb, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

**** Fortran interface

#+begin_src f90 :tangle (eval fh_func) :comments org
interface
   integer(qmckl_exit_code) function qmckl_get_jastrow_asymp_jasb(context, &
        asymp_jasb, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(in), value       :: size_max
     double precision, intent(out)               :: asymp_jasb(size_max)
   end function qmckl_get_jastrow_asymp_jasb
end interface
#+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_jastrow_asymp_jasb(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_jastrow_asymp_jasb(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_provide_jastrow_asymp_jasb",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!ctx->jastrow.provided) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_provide_jastrow_asymp_jasb",
                           NULL);
  }

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.asymp_jasb_date) {

    /* Allocate array */
    if (ctx->jastrow.asymp_jasb == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = 2 * sizeof(double);
      double* asymp_jasb = (double*) qmckl_malloc(context, mem_info);

      if (asymp_jasb == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_asymp_jasb",
                               NULL);
      }
      ctx->jastrow.asymp_jasb = asymp_jasb;
    }

    rc = qmckl_compute_jastrow_asymp_jasb(context,
                                  ctx->jastrow.bord_num,
                                  ctx->jastrow.b_vector,
                                  ctx->jastrow.rescale_factor_ee,
                                  ctx->jastrow.asymp_jasb);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.asymp_jasb_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_jastrow_asymp_jasb
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_asymp_jasb_args
    | Variable            | Type                 | In/Out | Description             |
    |---------------------+----------------------+--------+-------------------------|
    | ~context~           | ~qmckl_context~      | in     | Global state            |
    | ~bord_num~          | ~int64_t~            | in     | Order of the polynomial |
    | ~b_vector~          | ~double[bord_num+1]~ | in     | Values of b             |
    | ~rescale_factor_ee~ | ~double~             | in     | Electron coordinates    |
    | ~asymp_jasb~        | ~double[2]~          | out    | Asymptotic value        |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_jastrow_asymp_jasb_f(context, bord_num, b_vector, rescale_factor_ee, asymp_jasb) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: bord_num
  double precision      , intent(in)  :: b_vector(bord_num + 1)
  double precision      , intent(in)  :: rescale_factor_ee
  double precision      , intent(out) :: asymp_jasb(2)

  integer*8 :: i, p
  double precision   :: kappa_inv, x, asym_one
  kappa_inv = 1.0d0 / rescale_factor_ee

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (bord_num < 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  asym_one = b_vector(1) * kappa_inv / (1.0d0 + b_vector(2) * kappa_inv)
  asymp_jasb(:) = (/asym_one, 0.5d0 * asym_one/)

  do i = 1, 2
     x = kappa_inv
     do p = 2, bord_num
        x = x * kappa_inv
        asymp_jasb(i) = asymp_jasb(i) + b_vector(p + 1) * x
     end do
  end do

end function qmckl_compute_jastrow_asymp_jasb_f
    #+end_src

#+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_jastrow_asymp_jasb (
	  const qmckl_context context,
	  const int64_t bord_num,
	  const double* b_vector,
	  const double rescale_factor_ee,
	  double* const asymp_jasb ) {

    if (context == QMCKL_NULL_CONTEXT){
      return QMCKL_INVALID_CONTEXT;
    }

    if (bord_num < 0) {
      return QMCKL_INVALID_ARG_2;
    }

    const double kappa_inv = 1.0 / rescale_factor_ee;
    const double asym_one = b_vector[0] * kappa_inv / (1.0 + b_vector[1] * kappa_inv);
    asymp_jasb[0] = asym_one;
    asymp_jasb[1] = 0.5 * asym_one;

    for (int i = 0 ; i <= 1; ++i) {
      double x = kappa_inv;
      for (int p = 1; p < bord_num; ++p){
        x *= kappa_inv;
        asymp_jasb[i] = asymp_jasb[i] + b_vector[p + 1] * x;
      }
    }

  return QMCKL_SUCCESS;
}
#+end_src

#   #+CALL: generate_c_header(table=qmckl_asymp_jasb_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_jastrow_asymp_jasb (
          const qmckl_context context,
          const int64_t bord_num,
          const double* b_vector,
          const double rescale_factor_ee,
          double* const asymp_jasb );
    #+end_src

*** Test
    #+name: asymp_jasb
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

asym_one = b_vector[0] * kappa_inv / (1.0 + b_vector[1]*kappa_inv)
asymp_jasb = np.array([asym_one, 0.5 * asym_one])

for i in range(2):
  x = kappa_inv
  for p in range(1,bord_num):
    x = x * kappa_inv
    asymp_jasb[i] += b_vector[p + 1] * x

print("asym_one         : ", asym_one)
print("asymp_jasb[0]    : ", asymp_jasb[0])
print("asymp_jasb[1]    : ", asymp_jasb[1])
    #+end_src

    #+RESULTS: asymp_jasb
    : asym_one         :  0.43340325572525706
    : asymp_jasb[0]    :  0.5323750557252571
    : asymp_jasb[1]    :  0.31567342786262853

     #+begin_src c :tangle (eval c_test)
assert(qmckl_electron_provided(context));

int64_t type_nucl_num = n2_type_nucl_num;
int64_t* type_nucl_vector = &(n2_type_nucl_vector[0]);
int64_t aord_num = n2_aord_num;
int64_t bord_num = n2_bord_num;
int64_t cord_num = n2_cord_num;
double* a_vector = &(n2_a_vector[0][0]);
double* b_vector = &(n2_b_vector[0]);
double* c_vector = &(n2_c_vector[0][0]);
int64_t dim_c_vector=0;

assert(!qmckl_jastrow_provided(context));

/* Set the data */
rc = qmckl_check(context,
                 qmckl_set_jastrow_aord_num(context, aord_num)
                 );
rc = qmckl_check(context,
                 qmckl_set_jastrow_bord_num(context, bord_num)
                 );
rc = qmckl_check(context,
                 qmckl_set_jastrow_cord_num(context, cord_num)
                 );
assert(rc == QMCKL_SUCCESS);
rc = qmckl_check(context,
                 qmckl_set_jastrow_type_nucl_num(context, type_nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);
rc = qmckl_check(context,
                 qmckl_set_jastrow_type_nucl_vector(context, type_nucl_vector, nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);
rc = qmckl_check(context,
                 qmckl_set_jastrow_a_vector(context, a_vector,(aord_num+1)*type_nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);
rc = qmckl_check(context,
                 qmckl_set_jastrow_b_vector(context, b_vector,(bord_num+1))
                 );
assert(rc == QMCKL_SUCCESS);
rc = qmckl_check(context,
                 qmckl_get_jastrow_dim_c_vector(context, &dim_c_vector)
                 );
assert(rc == QMCKL_SUCCESS);
rc = qmckl_check(context,
                 qmckl_set_jastrow_c_vector(context, c_vector,dim_c_vector*type_nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);

double k_ee = 0.;
double k_en[2] = { 0., 0. };
rc = qmckl_check(context,
                 qmckl_set_jastrow_rescale_factor_en(context, rescale_factor_en, type_nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);

rc = qmckl_check(context,
                 qmckl_set_jastrow_rescale_factor_ee(context, rescale_factor_ee)
                 );
assert(rc == QMCKL_SUCCESS);

rc = qmckl_check(context,
                 qmckl_get_jastrow_rescale_factor_ee (context, &k_ee)
                 );
assert(rc == QMCKL_SUCCESS);
assert(k_ee == rescale_factor_ee);

rc = qmckl_check(context,
                 qmckl_get_jastrow_rescale_factor_en (context, &(k_en[0]), type_nucl_num)
                 );
assert(rc == QMCKL_SUCCESS);
for (int i=0 ; i<type_nucl_num ; ++i) {
  assert(k_en[i] == rescale_factor_en[i]);
 }

/* Check if Jastrow is properly initialized */
assert(qmckl_jastrow_provided(context));

double asymp_jasb[2];
rc = qmckl_get_jastrow_asymp_jasb(context, asymp_jasb,2);

// calculate asymp_jasb
assert(fabs(asymp_jasb[0]-0.5323750557252571) < 1.e-12);
assert(fabs(asymp_jasb[1]-0.31567342786262853) < 1.e-12);

     #+end_src

** Electron-electron component \(f_{ee}\)

  Calculate the electron-electron jastrow component ~factor_ee~ using the ~asymp_jasb~
  componenet and the electron-electron rescaled distances ~ee_distance_rescaled~.

  \[
f_{ee} = \sum_{i,j<i} \left[ \frac{ \eta B_0 C_{ij}}{1 - B_1 C_{ij}}  + \sum^{nord}_{k}B_k C_{ij}^k \right] - J_{\text{ee}}^{\infty}
  \]

  $\eta$ is the spin factor, $B$ is the vector of $b$ parameters,
  $C$ is the array of scaled distances.


*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_factor_ee(qmckl_context context,
                            double* const factor_ee,
                            const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_factor_ee(qmckl_context context,
                            double* const factor_ee,
                            const int64_t size_max)
{
  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_get_jastrow_factor_ee",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  rc = qmckl_provide_jastrow_factor_ee(context);
  if (rc != QMCKL_SUCCESS) return rc;

  int64_t sze=ctx->electron.walker.num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_ee",
                           "Array too small. Expected walker.num");
  }
  memcpy(factor_ee, ctx->jastrow.factor_ee, sze*sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

**** Fortran interface

#+begin_src f90 :tangle (eval fh_func) :comments org
interface
   integer(qmckl_exit_code) function qmckl_get_jastrow_factor_ee (context, &
        factor_ee, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(in), value       :: size_max
     double precision, intent(out)               :: factor_ee(size_max)
   end function qmckl_get_jastrow_factor_ee
end interface
#+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_ee(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_ee(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_provide_jastrow_factor_ee",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!ctx->jastrow.provided) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_provide_jastrow_factor_ee",
                           NULL);
  }

  rc = qmckl_provide_ee_distance_rescaled(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Provided in finalize_jastrow */
  /*
  rc = qmckl_provide_jastrow_asymp_jasb(context);
  if(rc != QMCKL_SUCCESS) return rc;
  */

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.factor_ee_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.factor_ee != NULL) {
        rc = qmckl_free(context, ctx->jastrow.factor_ee);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_jastrow_factor_ee",
                                 "Unable to free ctx->jastrow.factor_ee");
        }
        ctx->jastrow.factor_ee = NULL;
      }
    }
    
    /* Allocate array */
    if (ctx->jastrow.factor_ee == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walker.num * sizeof(double);
      double* factor_ee = (double*) qmckl_malloc(context, mem_info);

      if (factor_ee == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_jastrow_factor_ee",
                               NULL);
      }
      ctx->jastrow.factor_ee = factor_ee;
    }

    rc = qmckl_compute_factor_ee(context,
                                 ctx->electron.walker.num,
                                 ctx->electron.num,
                                 ctx->electron.up_num,
                                 ctx->jastrow.bord_num,
                                 ctx->jastrow.b_vector,
                                 ctx->jastrow.ee_distance_rescaled,
                                 ctx->jastrow.asymp_jasb,
                                 ctx->jastrow.factor_ee);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.factor_ee_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_ee
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_ee_args
    | Variable               | Type                                   | In/Out | Description                 |
    |------------------------+----------------------------------------+--------+-----------------------------|
    | ~context~              | ~qmckl_context~                        | in     | Global state                |
    | ~walk_num~             | ~int64_t~                              | in     | Number of walkers           |
    | ~elec_num~             | ~int64_t~                              | in     | Number of electrons         |
    | ~up_num~               | ~int64_t~                              | in     | Number of alpha electrons   |
    | ~bord_num~             | ~int64_t~                              | in     | Number of coefficients      |
    | ~b_vector~             | ~double[bord_num+1]~                   | in     | List of coefficients        |
    | ~ee_distance_rescaled~ | ~double[walk_num][elec_num][elec_num]~ | in     | Electron-electron distances |
    | ~asymp_jasb~           | ~double[2]~                            | in     | Electron-electron distances |
    | ~factor_ee~            | ~double[walk_num]~                     | out    | Electron-electron distances |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_ee_f(context, walk_num, elec_num, up_num, bord_num,            &
                                           b_vector, ee_distance_rescaled, asymp_jasb, factor_ee) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, bord_num, up_num
  double precision      , intent(in)  :: b_vector(bord_num + 1)
  double precision      , intent(in)  :: ee_distance_rescaled(elec_num, elec_num, walk_num)
  double precision      , intent(in)  :: asymp_jasb(2)
  double precision      , intent(out) :: factor_ee(walk_num)

  integer*8 :: i, j, p, ipar, nw
  double precision   :: x, power_ser, spin_fact

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif
  
  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif
  
  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif
  
  if (bord_num < 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif
  
  factor_ee = 0.0d0
  
  do nw =1, walk_num
     do j = 1, elec_num
        do i = 1, j - 1
           x = ee_distance_rescaled(i,j,nw)
           power_ser = 0.0d0
           spin_fact = 1.0d0
           ipar = 1
           
           do p = 2, bord_num
              x = x * ee_distance_rescaled(i,j,nw)
              power_ser = power_ser + b_vector(p + 1) * x
           end do
           
           if(j <= up_num .or. i > up_num) then
              spin_fact = 0.5d0
              ipar = 2
           endif
           
           factor_ee(nw) = factor_ee(nw) + spin_fact * b_vector(1)  * &
                ee_distance_rescaled(i,j,nw) / &
                (1.0d0 + b_vector(2) *   &
                ee_distance_rescaled(i,j,nw))  &
                + power_ser - asymp_jasb(ipar) 
           
        end do
     end do
  end do

end function qmckl_compute_factor_ee_f
    #+end_src

#+begin_src c   :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_factor_ee (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t up_num,
      const int64_t bord_num,
      const double* b_vector,
      const double* ee_distance_rescaled,
      const double* asymp_jasb,
      double* const factor_ee ) {

  int ipar;
  double x, x1, spin_fact, power_ser;

  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (walk_num <= 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
     return QMCKL_INVALID_ARG_3;
  }

  if (bord_num < 0) {
     return QMCKL_INVALID_ARG_4;
  }

  for (int nw = 0; nw < walk_num; ++nw) {
    factor_ee[nw] = 0.0; // put init array here.
    for (int i = 0; i < elec_num; ++i ) {
      for (int j = 0; j < i; ++j) {
        //x = ee_distance_rescaled[j * (walk_num * elec_num) + i * (walk_num) + nw];
        x = ee_distance_rescaled[j + i * elec_num + nw*(elec_num * elec_num)];
        x1 = x;
        power_ser = 0.0;
        spin_fact = 1.0;
        ipar = 0; // index of asymp_jasb

        for (int p = 1; p < bord_num; ++p) {
          x = x * x1;
          power_ser = power_ser + b_vector[p + 1] * x;
        }

        if(i < up_num || j >= up_num) {
          spin_fact = 0.5;
          ipar = 1;
        }

        factor_ee[nw] = factor_ee[nw] + spin_fact * b_vector[0]  * 
                                x1 / (1.0 + b_vector[1] * x1)   
                               - asymp_jasb[ipar] + power_ser;

      }
    }
  }

  return QMCKL_SUCCESS;
}
#+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_ee_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_ee (
          const qmckl_context context,
          const int64_t walk_num,
          const int64_t elec_num,
          const int64_t up_num,
          const int64_t bord_num,
          const double* b_vector,
          const double* ee_distance_rescaled,
          const double* asymp_jasb,
          double* const factor_ee );
    #+end_src

*** Test
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

<<asymp_jasb>>

factor_ee = 0.0
for i in range(0,elec_num):
  for j in range(0,i):
    x = ee_distance_rescaled[i][j]
    pow_ser = 0.0
    spin_fact = 1.0
    ipar = 0

    for p in range(1,bord_num):
      x = x * ee_distance_rescaled[i][j]
      pow_ser = pow_ser + b_vector[p + 1] * x

    if(i < up_num or j >= up_num):
      spin_fact = 0.5
      ipar = 1

    factor_ee = factor_ee + spin_fact * b_vector[0] * ee_distance_rescaled[i][j] \
                          / (1.0 + b_vector[1] * ee_distance_rescaled[i][j])     \
                          - asymp_jasb[ipar] + pow_ser
print("factor_ee        :",factor_ee)

    #+end_src

    #+RESULTS:
    : asym_one         :  0.43340325572525706
    : asymp_jasb[0]    :  0.5323750557252571
    : asymp_jasb[1]    :  0.31567342786262853
    : factor_ee        : -4.282760865958113


     #+begin_src c :tangle (eval c_test)
/* Check if Jastrow is properly initialized */
assert(qmckl_jastrow_provided(context));

double factor_ee[walk_num];
rc = qmckl_check(context,
                 qmckl_get_jastrow_factor_ee(context, factor_ee, walk_num)
                 );

// calculate factor_ee
printf("%e\n%e\n\n",factor_ee[0],-4.282760865958113 );
assert(fabs(factor_ee[0]+4.282760865958113) < 1.e-12);

     #+end_src

** Electron-electron component derivative \(f'_{ee}\)

  Calculate the derivative of the ~factor_ee~ using the ~ee_distance_rescaled~ and
  the electron-electron rescaled distances derivatives ~ee_distance_rescaled_deriv_e~.
  There are four components, the gradient which has 3 components in the \(x, y, z\)
  directions and the laplacian as the last component.

 # TODO: Add equation

*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_factor_ee_deriv_e(qmckl_context context,
                                    double* const factor_ee_deriv_e,
                                    const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_factor_ee_deriv_e(qmckl_context context,
                                    double* const factor_ee_deriv_e,
                                    const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_factor_ee_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.walker.num * 4 * ctx->electron.num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_ee_deriv_e",
                           "Array too small. Expected 4*walk_num*elec_num");
  }

  memcpy(factor_ee_deriv_e, ctx->jastrow.factor_ee_deriv_e, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_ee_deriv_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_ee_deriv_e(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_provide_jastrow_factor_ee_deriv_e",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!ctx->jastrow.provided) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_provide_jastrow_factor_ee_deriv_e",
                           NULL);
  }

  /* Check if ee rescaled distance is provided */
  rc = qmckl_provide_ee_distance_rescaled(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if ee rescaled distance deriv e is provided */
  rc = qmckl_provide_ee_distance_rescaled_deriv_e(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.factor_ee_deriv_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.factor_ee_deriv_e != NULL) {
        rc = qmckl_free(context, ctx->jastrow.factor_ee_deriv_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_jastrow_factor_ee_deriv_e",
                                 "Unable to free ctx->jastrow.factor_ee_deriv_e");
        }
        ctx->jastrow.factor_ee_deriv_e = NULL;
      }
    }
    
    /* Allocate array */
    if (ctx->jastrow.factor_ee_deriv_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walker.num * 4 * ctx->electron.num * sizeof(double);
      double* factor_ee_deriv_e = (double*) qmckl_malloc(context, mem_info);

      if (factor_ee_deriv_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_jastrow_factor_ee_deriv_e",
                               NULL);
      }
      ctx->jastrow.factor_ee_deriv_e = factor_ee_deriv_e;
    }

    rc = qmckl_compute_factor_ee_deriv_e(context,
                                         ctx->electron.walker.num,
                                         ctx->electron.num,
                                         ctx->electron.up_num,
                                         ctx->jastrow.bord_num,
                                         ctx->jastrow.b_vector,
                                         ctx->jastrow.ee_distance_rescaled,
                                         ctx->jastrow.ee_distance_rescaled_deriv_e,
                                         ctx->jastrow.factor_ee_deriv_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.factor_ee_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_ee_deriv_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_ee_deriv_e_args
    | Variable                       | Type                                      | In/Out | Description                 |
    |--------------------------------+-------------------------------------------+--------+-----------------------------|
    | ~context~                      | ~qmckl_context~                           | in     | Global state                |
    | ~walk_num~                     | ~int64_t~                                 | in     | Number of walkers           |
    | ~elec_num~                     | ~int64_t~                                 | in     | Number of electrons         |
    | ~up_num~                       | ~int64_t~                                 | in     | Number of alpha electrons   |
    | ~bord_num~                     | ~int64_t~                                 | in     | Number of coefficients      |
    | ~b_vector~                     | ~double[bord_num+1]~                      | in     | List of coefficients        |
    | ~ee_distance_rescaled~         | ~double[walk_num][elec_num][elec_num]~    | in     | Electron-electron distances |
    | ~ee_distance_rescaled_deriv_e~ | ~double[walk_num][4][elec_num][elec_num]~ | in     | Electron-electron distances |
    | ~factor_ee_deriv_e~            | ~double[walk_num][4][elec_num]~           | out    | Electron-electron distances |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_ee_deriv_e_doc_f( &
     context, walk_num, elec_num, up_num, bord_num, &
     b_vector, ee_distance_rescaled, ee_distance_rescaled_deriv_e,  &
     factor_ee_deriv_e) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, bord_num, up_num
  double precision      , intent(in)  :: b_vector(bord_num + 1)
  double precision      , intent(in)  :: ee_distance_rescaled(elec_num, elec_num,walk_num)
  double precision      , intent(in)  :: ee_distance_rescaled_deriv_e(4,elec_num, elec_num,walk_num)   !TODO
  double precision      , intent(out) :: factor_ee_deriv_e(elec_num,4,walk_num)

  integer*8 :: i, j, p, nw, ii
  double precision   :: x, spin_fact, y
  double precision   :: den, invden, invden2, invden3, xinv
  double precision   :: lap1, lap2, lap3, third
  double precision, dimension(3) :: pow_ser_g
  double precision, dimension(4) :: dx

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (bord_num < 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  factor_ee_deriv_e = 0.0d0
  third = 1.0d0 / 3.0d0

  do nw =1, walk_num
  do j = 1, elec_num
     do i = 1, elec_num
        x = ee_distance_rescaled(i,j,nw)
        if(abs(x) < 1.0d-18) cycle
        pow_ser_g   = 0.0d0
        spin_fact   = 1.0d0
        den         = 1.0d0 + b_vector(2) * x
        invden      = 1.0d0 / den
        invden2     = invden * invden
        invden3     = invden2 * invden
        xinv        = 1.0d0 / (x + 1.0d-18)

        dx(1) = ee_distance_rescaled_deriv_e(1, i, j, nw)
        dx(2) = ee_distance_rescaled_deriv_e(2, i, j, nw)
        dx(3) = ee_distance_rescaled_deriv_e(3, i, j, nw)
        dx(4) = ee_distance_rescaled_deriv_e(4, i, j, nw)

        if((i .LE. up_num .AND. j .LE. up_num ) .OR.  &
           (i .GT. up_num .AND. j .GT. up_num)) then
          spin_fact = 0.5d0
        endif

        lap1 = 0.0d0
        lap2 = 0.0d0
        lap3 = 0.0d0
        do ii = 1, 3
          x = ee_distance_rescaled(i, j, nw)
          if(abs(x) < 1.0d-18) cycle
          do p = 2, bord_num
            y = p * b_vector(p + 1) * x
            pow_ser_g(ii) = pow_ser_g(ii) + y * dx(ii)
            lap1 = lap1 + (p - 1) * y * xinv * dx(ii) * dx(ii)
            lap2 = lap2 + y
            x = x * ee_distance_rescaled(i, j, nw)
          end do

          lap3 = lap3 - 2.0d0 * b_vector(2) * dx(ii) * dx(ii)

          factor_ee_deriv_e( j, ii, nw) = factor_ee_deriv_e( j, ii, nw) + spin_fact * b_vector(1)  * &
                                dx(ii) * invden2 + pow_ser_g(ii)
        end do

        ii = 4
        lap2 = lap2 * dx(ii) * third
        lap3 = lap3 + den * dx(ii)
        lap3 = lap3 * (spin_fact * b_vector(1) * invden3)
        factor_ee_deriv_e( j, ii, nw) = factor_ee_deriv_e( j, ii, nw) + lap1 + lap2 + lap3

     end do
  end do
  end do

end function qmckl_compute_factor_ee_deriv_e_doc_f
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_factor_ee_deriv_e_hpc(
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t up_num,
      const int64_t bord_num,
      const double* b_vector,
      const double* ee_distance_rescaled,
      const double* ee_distance_rescaled_deriv_e,
      double* const factor_ee_deriv_e ) {

  double  pow_ser_g[3];
  double  dx[4];
  double  x, spin_fact, y;
  double  den, invden, invden2, invden3, xinv;
  double  lap1, lap2, lap3, third;

  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  } 

  if (walk_num <= 0) {
    return QMCKL_INVALID_ARG_2;
  } 

  if (elec_num <= 0) {
    return QMCKL_INVALID_ARG_3;
  }

  if (bord_num < 0) {
    return QMCKL_INVALID_ARG_4;
  }

  
  for (int nw = 0; nw < walk_num; ++nw) {
    for (int ii = 0; ii < 4; ++ii) {
      for (int j = 0; j < elec_num; ++j) {
        factor_ee_deriv_e[j + ii * elec_num + nw * elec_num * 4]  = 0.0;
      }
    }
  }
  
  third = 1.0 / 3.0;

  for (int nw = 0; nw < walk_num; ++nw) {
    for (int i = 0; i < elec_num; ++i) {
      for (int j = 0; j < elec_num; ++j) {
        x = ee_distance_rescaled[j + i * elec_num + nw * elec_num * elec_num];
        if (fabs(x) < 1.0e-18) continue;
        for (int ii = 0; ii < 3; ++ii){
            pow_ser_g[ii] = 0.0;
        }    
        spin_fact   = 1.0;
        den         = 1.0 + b_vector[1] * x;
        invden      = 1.0 / den;
        invden2     = invden * invden;
        invden3     = invden2 * invden;
        xinv        = 1.0 / (x + 1.0e-18);
        
        dx[0] = ee_distance_rescaled_deriv_e[0 \
                                           + j * 4 + i * 4 * elec_num \
                                           + nw * 4 * elec_num * elec_num];
        dx[1] = ee_distance_rescaled_deriv_e[1  \
                                           + j * 4 + i * 4 * elec_num \
                                           + nw * 4 * elec_num * elec_num];
        dx[2] = ee_distance_rescaled_deriv_e[2  \
                                           + j * 4 + i * 4 * elec_num \
                                           + nw * 4 * elec_num * elec_num];
        dx[3] = ee_distance_rescaled_deriv_e[3  \
                                           + j * 4 + i * 4 * elec_num \
                                           + nw * 4 * elec_num * elec_num];

        if((i <= (up_num-1) && j <= (up_num-1) ) || (i > (up_num-1) && j > (up_num-1))) {
          spin_fact = 0.5;
        }

        lap1 = 0.0;
        lap2 = 0.0;
        lap3 = 0.0;
        for (int ii = 0; ii < 3; ++ii) {
          x = ee_distance_rescaled[j + i * elec_num + nw * elec_num * elec_num];
          if (fabs(x) < 1.0e-18) continue;
          for (int p = 2; p < bord_num+1; ++p) {
            y = p * b_vector[(p-1) + 1] * x;
            pow_ser_g[ii] = pow_ser_g[ii] + y * dx[ii];
            lap1 = lap1 + (p - 1) * y * xinv * dx[ii] * dx[ii];
            lap2 = lap2 + y;
            x = x * ee_distance_rescaled[j + i * elec_num + nw * elec_num * elec_num];
          }

          lap3 = lap3 - 2.0 * b_vector[1] * dx[ii] * dx[ii];

          factor_ee_deriv_e[i  + ii * elec_num  + nw * elec_num * 4 ] +=              \
                                       + spin_fact * b_vector[0] * dx[ii] * invden2 \
                                       + pow_ser_g[ii] ;
        }

        int ii = 3;
        lap2 = lap2 * dx[ii] * third;
        lap3 = lap3 + den * dx[ii];
        lap3 = lap3 * (spin_fact * b_vector[0] * invden3);
        factor_ee_deriv_e[i + ii*elec_num + nw * elec_num * 4] += lap1 + lap2 + lap3;

      }
    }
  }
  
  return QMCKL_SUCCESS;
}
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_ee_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))


    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_ee_deriv_e (
          const qmckl_context context,
          const int64_t walk_num,
          const int64_t elec_num,
          const int64_t up_num,
          const int64_t bord_num,
          const double* b_vector,
          const double* ee_distance_rescaled,
          const double* ee_distance_rescaled_deriv_e,
          double* const factor_ee_deriv_e );
    #+end_src


    #+CALL: generate_c_interface(table=qmckl_factor_ee_deriv_e_args,rettyp=get_value("CRetType"),fname="qmckl_compute_factor_ee_deriv_e_doc")

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
integer(c_int32_t) function qmckl_compute_factor_ee_deriv_e_doc &
    (context, &
         walk_num, &
         elec_num, &
         up_num, &
         bord_num, &
         b_vector, &
         ee_distance_rescaled, &
         ee_distance_rescaled_deriv_e, &
         factor_ee_deriv_e) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: up_num
      integer (c_int64_t) , intent(in)  , value :: bord_num
      real    (c_double ) , intent(in)          :: b_vector(bord_num+1)
      real    (c_double ) , intent(in)          :: ee_distance_rescaled(elec_num,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: ee_distance_rescaled_deriv_e(elec_num,elec_num,4,walk_num)
      real    (c_double ) , intent(out)         :: factor_ee_deriv_e(elec_num,4,walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_ee_deriv_e_doc_f
      info = qmckl_compute_factor_ee_deriv_e_doc_f &
         (context, &
         walk_num, &
         elec_num, &
         up_num, &
         bord_num, &
         b_vector, &
         ee_distance_rescaled, &
         ee_distance_rescaled_deriv_e, &
         factor_ee_deriv_e)

    end function qmckl_compute_factor_ee_deriv_e_doc
    #+end_src
    
    #+begin_src c :tangle (eval h_private_func) :comments org
    qmckl_exit_code qmckl_compute_factor_ee_deriv_e_hpc (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t up_num,
      const int64_t bord_num,
      const double* b_vector,
      const double* ee_distance_rescaled,
      const double* ee_distance_rescaled_deriv_e,
      double* const factor_ee_deriv_e );

    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org
    qmckl_exit_code qmckl_compute_factor_ee_deriv_e_doc (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t up_num,
      const int64_t bord_num,
      const double* b_vector,
      const double* ee_distance_rescaled,
      const double* ee_distance_rescaled_deriv_e,
      double* const factor_ee_deriv_e );
    #+end_src


    #+begin_src c :comments org :tangle (eval c) :noweb yes
    qmckl_exit_code qmckl_compute_factor_ee_deriv_e (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t up_num,
      const int64_t bord_num,
      const double* b_vector,
      const double* ee_distance_rescaled,
      const double* ee_distance_rescaled_deriv_e,
      double* const factor_ee_deriv_e ) {

      #ifdef HAVE_HPC
      return qmckl_compute_factor_ee_deriv_e_hpc(context, walk_num, elec_num, up_num, bord_num, b_vector, ee_distance_rescaled, ee_distance_rescaled_deriv_e, factor_ee_deriv_e ); 
      #else
      return qmckl_compute_factor_ee_deriv_e_doc(context, walk_num, elec_num, up_num, bord_num, b_vector, ee_distance_rescaled, ee_distance_rescaled_deriv_e, factor_ee_deriv_e ); 
      #endif
}
    #+end_src




*** Test
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

<<asymp_jasb>>

kappa = 1.0

elec_coord = np.array(elec_coord)[0]
elec_dist = np.zeros(shape=(elec_num, elec_num),dtype=float)
for i in range(elec_num):
  for j in range(elec_num):
    elec_dist[i, j] = np.linalg.norm(elec_coord[i] - elec_coord[j])

elec_dist_deriv_e = np.zeros(shape=(4,elec_num, elec_num),dtype=float)
for j in range(elec_num):
  for i in range(elec_num):
    rij_inv = 1.0 / elec_dist[i, j]
    for ii in range(3):
      elec_dist_deriv_e[ii, i, j] = (elec_coord[j][ii] - elec_coord[i][ii]) * rij_inv
    elec_dist_deriv_e[3, i, j] = 2.0 * rij_inv
  elec_dist_deriv_e[:, j, j] = 0.0

ee_distance_rescaled_deriv_e = np.zeros(shape=(4,elec_num,elec_num),dtype=float)
for j in range(elec_num):
  for i in range(elec_num):
    f = 1.0 - kappa * ee_distance_rescaled[i][j]
    for ii in range(4):
      ee_distance_rescaled_deriv_e[ii][i][j] = elec_dist_deriv_e[ii][i][j]
    ee_distance_rescaled_deriv_e[3][i][j] = ee_distance_rescaled_deriv_e[3][i][j] + \
                              (-kappa * ee_distance_rescaled_deriv_e[0][i][j] * ee_distance_rescaled_deriv_e[0][i][j]) + \
                              (-kappa * ee_distance_rescaled_deriv_e[1][i][j] * ee_distance_rescaled_deriv_e[1][i][j]) + \
                              (-kappa * ee_distance_rescaled_deriv_e[2][i][j] * ee_distance_rescaled_deriv_e[2][i][j])
    for ii in range(4):
      ee_distance_rescaled_deriv_e[ii][i][j] = ee_distance_rescaled_deriv_e[ii][i][j] * f

third = 1.0 / 3.0
factor_ee_deriv_e = np.zeros(shape=(4,elec_num),dtype=float)
dx = np.zeros(shape=(4),dtype=float)
pow_ser_g = np.zeros(shape=(4),dtype=float)
for j in range(elec_num):
   for i in range(elec_num):
      x = ee_distance_rescaled[j][i]
      if abs(x) < 1e-18:
        continue
      pow_ser_g = np.zeros(shape=(4),dtype=float)
      spin_fact   = 1.0
      den         = 1.0 + b_vector[1] * ee_distance_rescaled[j][i]
      invden      = 1.0 / den
      invden2     = invden * invden
      invden3     = invden2 * invden
      xinv        = 1.0 / (ee_distance_rescaled[j][i] + 1.0E-18)
      ipar        = 1

      for ii in range(4):
        dx[ii] = ee_distance_rescaled_deriv_e[ii][j][i]

      if((i <= (up_num-1) and j <= (up_num-1) ) or  \
         (i >  (up_num-1) and j >  (up_num-1))):
        spin_fact = 0.5

      lap1 = 0.0
      lap2 = 0.0
      lap3 = 0.0
      for ii in range(3):
        x = ee_distance_rescaled[j][i]
        if x < 1e-18:
          continue
        for p in range(2,bord_num+1):
          y = p * b_vector[(p-1) + 1] * x
          pow_ser_g[ii] = pow_ser_g[ii] + y * dx[ii]
          lap1 = lap1 + (p - 1) * y * xinv * dx[ii] * dx[ii]
          lap2 = lap2 + y
          x = x * ee_distance_rescaled[j][i]

        lap3 = lap3 - 2.0 * b_vector[1] * dx[ii] * dx[ii]

        factor_ee_deriv_e[ii][j] = factor_ee_deriv_e[ii][j] + spin_fact * b_vector[0]  * \
                              dx[ii] * invden2 + pow_ser_g[ii]

      ii = 3
      lap2 = lap2 * dx[ii] * third
      lap3 = lap3 + den * dx[ii]
      lap3 = lap3 * (spin_fact * b_vector[0] * invden3)
      factor_ee_deriv_e[ii][j] = factor_ee_deriv_e[ii][j] + lap1 + lap2 + lap3

print("factor_ee_deriv_e[0][0]:",factor_ee_deriv_e[0][0])
print("factor_ee_deriv_e[1][0]:",factor_ee_deriv_e[1][0])
print("factor_ee_deriv_e[2][0]:",factor_ee_deriv_e[2][0])
print("factor_ee_deriv_e[3][0]:",factor_ee_deriv_e[3][0])
    #+end_src

    #+RESULTS:
    : asym_one         :  0.43340325572525706
    : asymp_jasb[0]    :  0.5323750557252571
    : asymp_jasb[1]    :  0.31567342786262853
    : factor_ee_deriv_e[0][0]: 0.16364894652107934
    : factor_ee_deriv_e[1][0]: -0.6927548119830084
    : factor_ee_deriv_e[2][0]: 0.073267755223968
    : factor_ee_deriv_e[3][0]: 1.5111672803213185


     #+begin_src c :tangle (eval c_test)
/* Check if Jastrow is properly initialized */
assert(qmckl_jastrow_provided(context));

// calculate factor_ee_deriv_e
double factor_ee_deriv_e[walk_num][4][elec_num];
rc = qmckl_get_jastrow_factor_ee_deriv_e(context, &(factor_ee_deriv_e[0][0][0]),walk_num*4*elec_num);

// check factor_ee_deriv_e
assert(fabs(factor_ee_deriv_e[0][0][0]-0.16364894652107934) < 1.e-12);
assert(fabs(factor_ee_deriv_e[0][1][0]+0.6927548119830084 ) < 1.e-12);
assert(fabs(factor_ee_deriv_e[0][2][0]-0.073267755223968  ) < 1.e-12);
assert(fabs(factor_ee_deriv_e[0][3][0]-1.5111672803213185 ) < 1.e-12);
     #+end_src

** Asymptotic component for \(J_{eN}\)

  Calculate the asymptotic component ~asymp_jasa~ to be substracted from the final
  electron-nucleus jastrow factor \(J_{\text{eN}}\). The asymptotic component is calculated
  via the ~a_vector~ and the electron-nucleus rescale factors ~rescale_factor_en~.

  \[
  J_{\text{en}}^{\infty \alpha} = \frac{a_1 \kappa_\alpha^{-1}}{1 + a_2  \kappa_\alpha^{-1}}
  \]

*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_asymp_jasa(qmckl_context context,
                             double* const asymp_jasa,
                             const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_asymp_jasa(qmckl_context context,
                             double* const asymp_jasa,
                             const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_get_jastrow_asymp_jasa",
                           NULL);
  }


  /* Provided in finalize_jastrow */
  /*
  qmckl_exit_code rc;
  rc = qmckl_provide_jastrow_asymp_jasa(context);
  if(rc != QMCKL_SUCCESS) return rc;
  */

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->jastrow.type_nucl_num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_asymp_jasa",
                           "Array too small. Expected nucleus.num");
  }
  memcpy(asymp_jasa, ctx->jastrow.asymp_jasa, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

**** Fortran interface

#+begin_src f90 :tangle (eval fh_func) :comments org
interface
   integer(qmckl_exit_code) function qmckl_get_jastrow_asymp_jasa(context, &
        asymp_jasa, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(in), value       :: size_max
     double precision, intent(out)               :: asymp_jasa(size_max)
   end function qmckl_get_jastrow_asymp_jasa
end interface
#+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_jastrow_asymp_jasa(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_jastrow_asymp_jasa(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_provide_jastrow_asymp_jasa",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!ctx->jastrow.provided) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_provide_jastrow_asymp_jasa",
                           NULL);
  }

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.asymp_jasa_date) {

    /* Allocate array */
    if (ctx->jastrow.asymp_jasa == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->jastrow.type_nucl_num * sizeof(double);
      double* asymp_jasa = (double*) qmckl_malloc(context, mem_info);

      if (asymp_jasa == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_asymp_jasa",
                               NULL);
      }
      ctx->jastrow.asymp_jasa = asymp_jasa;
    }

    rc = qmckl_compute_jastrow_asymp_jasa(context,
                                  ctx->jastrow.aord_num,
                                  ctx->jastrow.type_nucl_num,
                                  ctx->jastrow.a_vector,
                                  ctx->jastrow.rescale_factor_en,
                                  ctx->jastrow.asymp_jasa);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.asymp_jasa_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_jastrow_asymp_jasa
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_asymp_jasa_args
    | Variable            | Type                                | In/Out | Description                |
    |---------------------+-------------------------------------+--------+----------------------------|
    | ~context~           | ~qmckl_context~                     | in     | Global state               |
    | ~aord_num~          | ~int64_t~                           | in     | Order of the polynomial    |
    | ~type_nucl_num~     | ~int64_t~                           | in     | Number of nucleus types    |
    | ~a_vector~          | ~double[type_nucl_num][aord_num+1]~ | in     | Values of a                |
    | ~rescale_factor_en~ | ~double[type_nucl_num]~             | in     | Electron nucleus distances |
    | ~asymp_jasa~        | ~double[type_nucl_num]~             | out    | Asymptotic value           |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_jastrow_asymp_jasa_f(context, aord_num, type_nucl_num, a_vector, &
     rescale_factor_en, asymp_jasa) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: aord_num
  integer*8             , intent(in)  :: type_nucl_num
  double precision      , intent(in)  :: a_vector(aord_num + 1, type_nucl_num)
  double precision      , intent(in)  :: rescale_factor_en(type_nucl_num)
  double precision      , intent(out) :: asymp_jasa(type_nucl_num)

  integer*8 :: i, j, p
  double precision   :: kappa_inv, x, asym_one

  
  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (aord_num < 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  do i=1,type_nucl_num

     kappa_inv = 1.0d0 / rescale_factor_en(i)
     
     asymp_jasa(i) = a_vector(1,i) * kappa_inv / (1.0d0 + a_vector(2,i) * kappa_inv)
     
     x = kappa_inv
     do p = 2, aord_num
        x = x * kappa_inv
        asymp_jasa(i) = asymp_jasa(i) + a_vector(p+1, i) * x
     end do
     
  end do

end function qmckl_compute_jastrow_asymp_jasa_f
    #+end_src

   #+CALL: generate_c_interface(table=qmckl_asymp_jasa_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

   #+RESULTS:
   #+begin_src f90 :tangle (eval f) :comments org :exports none
   integer(c_int32_t) function qmckl_compute_jastrow_asymp_jasa &
       (context, aord_num, type_nucl_num, a_vector, rescale_factor_en, asymp_jasa) &
       bind(C) result(info)

     use, intrinsic :: iso_c_binding
     implicit none

     integer (c_int64_t) , intent(in)  , value :: context
     integer (c_int64_t) , intent(in)  , value :: aord_num
     integer (c_int64_t) , intent(in)  , value :: type_nucl_num
     real    (c_double ) , intent(in)          :: a_vector(aord_num+1,type_nucl_num)
     real    (c_double ) , intent(in)          :: rescale_factor_en(type_nucl_num)
     real    (c_double ) , intent(out)         :: asymp_jasa(type_nucl_num)

     integer(c_int32_t), external :: qmckl_compute_jastrow_asymp_jasa_f
     info = qmckl_compute_jastrow_asymp_jasa_f &
            (context, aord_num, type_nucl_num, a_vector, rescale_factor_en, asymp_jasa)

   end function qmckl_compute_jastrow_asymp_jasa
   #+end_src

#+begin_src c :comments org :tangle (eval c) :noweb yes
/*
qmckl_exit_code qmckl_compute_jastrow_asymp_jasa (
	  const qmckl_context context,
	  const int64_t aord_num,
	  const int64_t type_nucl_num,
	  const double* a_vector,
	  double* const rescale_factor_en,
	  double* const asymp_jasa ) {

    if (context == QMCKL_NULL_CONTEXT){
      return QMCKL_INVALID_CONTEXT;
    }

    if (aord_num < 0) {
      return QMCKL_INVALID_ARG_2;
    }

    for (int i = 0 ; i <= type_nucl_num; ++i) {
      const double kappa_inv = 1.0 / rescale_factor_en[i];
      asymp_jasa[i] =  a_vector[aord_num*i] * kappa_inv / (1.0 + a_vector[1 + aord_num*i] * kappa_inv);
      
      double x = kappa_inv;
      for (int p = 1; p < aord_num; ++p){
        x *= kappa_inv;
        asymp_jasa[i] = asymp_jasa[i] + a_vector[p + 1 + aord_num*i] * x;
      }
    }

  return QMCKL_SUCCESS;
}
*/
#+end_src

   #+CALL: generate_c_header(table=qmckl_asymp_jasa_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

   #+RESULTS:
   #+begin_src c :tangle (eval h_func) :comments org
   qmckl_exit_code qmckl_compute_jastrow_asymp_jasa (
         const qmckl_context context,
         const int64_t aord_num,
         const int64_t type_nucl_num,
         const double* a_vector,
         const double* rescale_factor_en,
         double* const asymp_jasa ); 
   #+end_src

*** Test
    #+name: asymp_jasa
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

asymp_jasa = a_vector[0] * kappa_inv / (1.0 + a_vector[1]*kappa_inv)
x = kappa_inv
for p in range(1,aord_num):
  x = x * kappa_inv
  asymp_jasa += a_vector[p + 1] * x
print("asymp_jasa[i]    : ", asymp_jasa)

    #+end_src

    #+RESULTS: asymp_jasa
    : asymp_jasa[i]    :  [-0.548554]

     #+begin_src c :tangle (eval c_test)
double asymp_jasa[2];
rc = qmckl_get_jastrow_asymp_jasa(context, asymp_jasa, type_nucl_num);

// calculate asymp_jasb
printf("%e %e\n", asymp_jasa[0], -0.548554);
assert(fabs(-0.548554 - asymp_jasa[0]) < 1.e-12);

     #+end_src

** Electron-nucleus component \(f_{en}\)

  Calculate the electron-electron jastrow component ~factor_en~ using the ~a_vector~
  coeffecients and the electron-nucleus rescaled distances ~en_distance_rescaled~.

  \[
f_{en} = \sum_{i,j<i} \left\{ \frac{ A_0 C_{ij}}{1 - A_1 C_{ij}} + \sum^{nord}_{k}A_k C_{ij}^k \right\}
  \]


*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_factor_en(qmckl_context context,
                            double* const factor_en,
                            const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_factor_en(qmckl_context context,
                            double* const factor_en,
                            const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_get_jastrow_factor_en",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_factor_en(context);
  if (rc != QMCKL_SUCCESS) return rc;

  int64_t sze=ctx->electron.walker.num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_en",
                           "Array too small. Expected walker.num");
  }
  memcpy(factor_en, ctx->jastrow.factor_en, sze*sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

**** Fortran interface

#+begin_src f90 :tangle (eval fh_func) :comments org
interface
   integer(qmckl_exit_code) function qmckl_get_jastrow_factor_en (context, &
        factor_en, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(in), value       :: size_max
     double precision, intent(out)               :: factor_en(size_max)
   end function qmckl_get_jastrow_factor_en
end interface
#+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_en(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_en(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_provide_jastrow_factor_en",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!ctx->jastrow.provided) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_provide_jastrow_factor_en",
                           NULL);
  }

  /* Check if en rescaled distance is provided */
  rc = qmckl_provide_en_distance_rescaled(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Provided in finalize_jastrow */
  /*
  rc = qmckl_provide_jastrow_asymp_jasa(context);
  if(rc != QMCKL_SUCCESS) return rc;
  */

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.factor_en_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.factor_en != NULL) {
        rc = qmckl_free(context, ctx->jastrow.factor_en);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_jastrow_factor_en",
                                 "Unable to free ctx->jastrow.factor_en");
        }
        ctx->jastrow.factor_en = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.factor_en == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walker.num * sizeof(double);
      double* factor_en = (double*) qmckl_malloc(context, mem_info);

      if (factor_en == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_jastrow_factor_en",
                               NULL);
      }
      ctx->jastrow.factor_en = factor_en;
    }

    rc = qmckl_compute_factor_en(context,
                                 ctx->electron.walker.num,
                                 ctx->electron.num,
                                 ctx->nucleus.num,
                                 ctx->jastrow.type_nucl_num,
                                 ctx->jastrow.type_nucl_vector,
                                 ctx->jastrow.aord_num,
                                 ctx->jastrow.a_vector,
                                 ctx->jastrow.en_distance_rescaled,
                                 ctx->jastrow.asymp_jasa,
                                 ctx->jastrow.factor_en);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }
    
    ctx->jastrow.factor_en_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_en
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_en_args
    | Variable               | Type                                   | In/Out | Description                |
    |------------------------+----------------------------------------+--------+----------------------------|
    | ~context~              | ~qmckl_context~                        | in     | Global state               |
    | ~walk_num~             | ~int64_t~                              | in     | Number of walkers          |
    | ~elec_num~             | ~int64_t~                              | in     | Number of electrons        |
    | ~nucl_num~             | ~int64_t~                              | in     | Number of nucleii          |
    | ~type_nucl_num~        | ~int64_t~                              | in     | Number of unique nuclei    |
    | ~type_nucl_vector~     | ~int64_t[nucl_num]~                    | in     | IDs of unique nucleii      |
    | ~aord_num~             | ~int64_t~                              | in     | Number of coefficients     |
    | ~a_vector~             | ~double[aord_num+1][type_nucl_num]~    | in     | List of coefficients       |
    | ~en_distance_rescaled~ | ~double[walk_num][nucl_num][elec_num]~ | in     | Electron-nucleus distances |
    | ~asymp_jasa~           | ~double[type_nucl_num]~                | in     | Type of nuclei             |
    | ~factor_en~            | ~double[walk_num]~                     | out    | Electron-nucleus jastrow   |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_en_f( &
     context, walk_num, elec_num, nucl_num, type_nucl_num, &
     type_nucl_vector, aord_num, a_vector, &
     en_distance_rescaled, asymp_jasa, factor_en) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, aord_num, nucl_num, type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  double precision      , intent(in)  :: a_vector(aord_num + 1, type_nucl_num)
  double precision      , intent(in)  :: en_distance_rescaled(elec_num, nucl_num, walk_num)
  double precision      , intent(in)  :: asymp_jasa(type_nucl_num)
  double precision      , intent(out) :: factor_en(walk_num)

  integer*8 :: i, a, p, nw
  double precision   :: x, power_ser

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (aord_num < 0) then
     info = QMCKL_INVALID_ARG_7
     return
  endif


  do nw =1, walk_num
     factor_en(nw) = 0.0d0
     do a = 1, nucl_num
        do i = 1, elec_num
           x = en_distance_rescaled(i, a, nw)

           factor_en(nw) = factor_en(nw) + a_vector(1, type_nucl_vector(a)) * x / &
                (1.0d0 + a_vector(2, type_nucl_vector(a)) * x) - asymp_jasa(type_nucl_vector(a))

           do p = 2, aord_num
              x = x * en_distance_rescaled(i, a, nw)
              factor_en(nw) = factor_en(nw) + a_vector(p + 1, type_nucl_vector(a)) * x
           end do

        end do
     end do
  end do

end function qmckl_compute_factor_en_f
    #+end_src


   #+CALL: generate_c_interface(table=qmckl_factor_en_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

   #+RESULTS:
   #+begin_src f90 :tangle (eval f) :comments org :exports none
   integer(c_int32_t) function qmckl_compute_factor_en &
       (context, &
        walk_num, &
        elec_num, &
        nucl_num, &
        type_nucl_num, &
        type_nucl_vector, &
        aord_num, &
        a_vector, &
        en_distance_rescaled, &
        asymp_jasa, &
        factor_en) &
       bind(C) result(info)

     use, intrinsic :: iso_c_binding
     implicit none

     integer (c_int64_t) , intent(in)  , value :: context
     integer (c_int64_t) , intent(in)  , value :: walk_num
     integer (c_int64_t) , intent(in)  , value :: elec_num
     integer (c_int64_t) , intent(in)  , value :: nucl_num
     integer (c_int64_t) , intent(in)  , value :: type_nucl_num
     integer (c_int64_t) , intent(in)          :: type_nucl_vector(nucl_num)
     integer (c_int64_t) , intent(in)  , value :: aord_num
     real    (c_double ) , intent(in)          :: a_vector(type_nucl_num,aord_num+1)
     real    (c_double ) , intent(in)          :: en_distance_rescaled(elec_num,nucl_num,walk_num)
     real    (c_double ) , intent(in)          :: asymp_jasa(type_nucl_num)
     real    (c_double ) , intent(out)         :: factor_en(walk_num)

     integer(c_int32_t), external :: qmckl_compute_factor_en_f
     info = qmckl_compute_factor_en_f &
            (context, &
        walk_num, &
        elec_num, &
        nucl_num, &
        type_nucl_num, &
        type_nucl_vector, &
        aord_num, &
        a_vector, &
        en_distance_rescaled, &
        asymp_jasa, &
        factor_en)

   end function qmckl_compute_factor_en
   #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
/*
qmckl_exit_code qmckl_compute_factor_en (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t type_nucl_num,
      const int64_t* type_nucl_vector,
      const int64_t aord_num,
      const double* a_vector,
      const double* en_distance_rescaled,
      const double* asymp_jasa,
      double* const factor_en ) {

  double  x, x1, power_ser;


  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (walk_num <= 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
     return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
     return QMCKL_INVALID_ARG_4;
  }

  if (type_nucl_num <= 0) {
    return QMCKL_INVALID_ARG_5;
  }

  if (type_nucl_vector == NULL) {
    return QMCKL_INVALID_ARG_6;
  }

  if (aord_num < 0) {
     return QMCKL_INVALID_ARG_7;
  }

  if (a_vector == NULL) {
    return QMCKL_INVALID_ARG_8;
  }

  if (en_distance_rescaled == NULL) {
    return QMCKL_INVALID_ARG_9;
  }

  if (factor_en == NULL) {
    return QMCKL_INVALID_ARG_10;
  }


  for (int nw = 0; nw < walk_num; ++nw ) {
    // init array
    factor_en[nw] = 0.0;
    for (int a = 0; a < nucl_num; ++a ) {
      for (int i = 0; i < elec_num; ++i ) {
        x = en_distance_rescaled[i + a * elec_num + nw * (elec_num * nucl_num)];
        x1 = x;
        power_ser = 0.0;

        for (int p = 2; p < aord_num+1; ++p) {
          x = x * x1;
          power_ser = power_ser + a_vector[p+ (type_nucl_vector[a]-1) * aord_num] * x;
        }

        factor_en[nw] = factor_en[nw] + a_vector[0 + (type_nucl_vector[a]-1)*aord_num] * x1 / \
                        (1.0 + a_vector[1 + (type_nucl_vector[a]-1) * aord_num] * x1) + \
                        power_ser;

      }
      factor_en[nw] = factor_en[nw] + asymp_jasa[type_nucl_vector[a];
    }
  }

  return QMCKL_SUCCESS;
}
*/
    #+end_src


   #+CALL: generate_c_header(table=qmckl_factor_en_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

   #+RESULTS:
   #+begin_src c :tangle (eval h_func) :comments org
   qmckl_exit_code qmckl_compute_factor_en (
         const qmckl_context context,
         const int64_t walk_num,
         const int64_t elec_num,
         const int64_t nucl_num,
         const int64_t type_nucl_num,
         const int64_t* type_nucl_vector,
         const int64_t aord_num,
         const double* a_vector,
         const double* en_distance_rescaled,
         const double* asymp_jasa,
         double* const factor_en ); 
   #+end_src

*** Test
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>
<<asymp_jasa>>

factor_en = 0.0
for a in range(0,nucl_num):
  for i in range(0,elec_num):
    x = en_distance_rescaled[i][a]
    pow_ser = 0.0

    for p in range(2,aord_num+1):
        x = x * en_distance_rescaled[i][a]
        pow_ser = pow_ser + a_vector[(p-1) + 1][type_nucl_vector[a]-1] * x

    factor_en = factor_en + a_vector[0][type_nucl_vector[a]-1] * x \
                          / (1.0 + a_vector[1][type_nucl_vector[a]-1] * x) \
                          + pow_ser
    factor_en -= asymp_jasa[type_nucl_vector[a]-1]
print("factor_en        :",factor_en)

    #+end_src

    #+RESULTS:
    : asymp_jasa[i]    :  [-0.548554]
    : factor_en        : 5.1052574308112755


     #+begin_src c :tangle (eval c_test)
/* Check if Jastrow is properly initialized */
assert(qmckl_jastrow_provided(context));

double factor_en[walk_num];
rc = qmckl_get_jastrow_factor_en(context, factor_en,walk_num);

// calculate factor_en
assert(fabs(5.1052574308112755 - factor_en[0]) < 1.e-12);

     #+end_src

** Electron-nucleus component derivative \(f'_{en}\)
  Calculate the electron-electron jastrow component ~factor_en_deriv_e~ derivative
  with respect to the electron coordinates using the ~en_distance_rescaled~ and
  ~en_distance_rescaled_deriv_e~ which are already calculated previously.

  TODO: write equations.

*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_factor_en_deriv_e(qmckl_context context,
                                    double* const factor_en_deriv_e,
                                    const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_factor_en_deriv_e(qmckl_context context,
                                    double* const factor_en_deriv_e,
                                    const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_factor_en_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.walker.num * 4 * ctx->electron.num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_en_deriv_e",
                           "Array too small. Expected 4*walker.num*elec_num");
  }
  memcpy(factor_en_deriv_e, ctx->jastrow.factor_en_deriv_e, sze*sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_en_deriv_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_jastrow_factor_en_deriv_e(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_provide_jastrow_factor_en_deriv_e",
                           NULL);
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!ctx->jastrow.provided) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_provide_jastrow_factor_en_deriv_e",
                           NULL);
  }

  /* Check if en rescaled distance is provided */
  rc = qmckl_provide_en_distance_rescaled(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_en_distance_rescaled_deriv_e(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.factor_en_deriv_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.factor_en_deriv_e != NULL) {
        rc = qmckl_free(context, ctx->jastrow.factor_en_deriv_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_jastrow_factor_en_deriv_e",
                                 "Unable to free ctx->jastrow.factor_en_deriv_e");
        }
        ctx->jastrow.factor_en_deriv_e = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.factor_en_deriv_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walker.num * 4 * ctx->electron.num * sizeof(double);
      double* factor_en_deriv_e = (double*) qmckl_malloc(context, mem_info);

      if (factor_en_deriv_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_jastrow_factor_en_deriv_e",
                               NULL);
      }
      ctx->jastrow.factor_en_deriv_e = factor_en_deriv_e;
    }

    rc = qmckl_compute_factor_en_deriv_e(context,
                                         ctx->electron.walker.num,
                                         ctx->electron.num,
                                         ctx->nucleus.num,
                                         ctx->jastrow.type_nucl_num,
                                         ctx->jastrow.type_nucl_vector,
                                         ctx->jastrow.aord_num,
                                         ctx->jastrow.a_vector,
                                         ctx->jastrow.en_distance_rescaled,
                                         ctx->jastrow.en_distance_rescaled_deriv_e,
                                         ctx->jastrow.factor_en_deriv_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.factor_en_deriv_e_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_en_deriv_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_en_deriv_e_args
    | Variable                       | Type                                      | In/Out | Description                           |
    |--------------------------------+-------------------------------------------+--------+---------------------------------------|
    | ~context~                      | ~qmckl_context~                           | in     | Global state                          |
    | ~walk_num~                     | ~int64_t~                                 | in     | Number of walkers                     |
    | ~elec_num~                     | ~int64_t~                                 | in     | Number of electrons                   |
    | ~nucl_num~                     | ~int64_t~                                 | in     | Number of nucleii                     |
    | ~type_nucl_num~                | ~int64_t~                                 | in     | Number of unique nuclei               |
    | ~type_nucl_vector~             | ~int64_t[nucl_num]~                       | in     | IDs of unique nucleii                 |
    | ~aord_num~                     | ~int64_t~                                 | in     | Number of coefficients                |
    | ~a_vector~                     | ~double[aord_num+1][type_nucl_num]~       | in     | List of coefficients                  |
    | ~en_distance_rescaled~         | ~double[walk_num][nucl_num][elec_num]~    | in     | Electron-nucleus distances            |
    | ~en_distance_rescaled_deriv_e~ | ~double[walk_num][4][nucl_num][elec_num]~ | in     | Electron-nucleus distance derivatives |
    | ~factor_en_deriv_e~            | ~double[walk_num][4][elec_num]~           | out    | Electron-nucleus jastrow              |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_en_deriv_e_f( &
     context, walk_num, elec_num, nucl_num, type_nucl_num, &
     type_nucl_vector, aord_num, a_vector, &
     en_distance_rescaled, en_distance_rescaled_deriv_e, factor_en_deriv_e) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, aord_num, nucl_num, type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  double precision      , intent(in)  :: a_vector(aord_num + 1, type_nucl_num)
  double precision      , intent(in)  :: en_distance_rescaled(elec_num, nucl_num, walk_num)
  double precision      , intent(in)  :: en_distance_rescaled_deriv_e(4, elec_num, nucl_num, walk_num)
  double precision      , intent(out) :: factor_en_deriv_e(elec_num,4,walk_num)

  integer*8 :: i, a, p, ipar, nw, ii
  double precision   :: x, den, invden, invden2, invden3, xinv
  double precision   :: y, lap1, lap2, lap3, third
  double precision, dimension(3) :: power_ser_g
  double precision, dimension(4) :: dx

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (aord_num < 0) then
     info = QMCKL_INVALID_ARG_7
     return
  endif

  factor_en_deriv_e = 0.0d0
  third = 1.0d0 / 3.0d0

  do nw =1, walk_num
  do a = 1, nucl_num
     do i = 1, elec_num
        x = en_distance_rescaled(i,a,nw)
        if(abs(x) < 1.0d-18) continue
        power_ser_g = 0.0d0
        den = 1.0d0 + a_vector(2, type_nucl_vector(a)) * x
        invden = 1.0d0 / den
        invden2 = invden * invden
        invden3 = invden2 * invden
        xinv = 1.0d0 / x

        do ii = 1, 4
          dx(ii) = en_distance_rescaled_deriv_e(ii,i,a,nw)
        end do

        lap1 = 0.0d0
        lap2 = 0.0d0
        lap3 = 0.0d0
        do ii = 1, 3
          x = en_distance_rescaled(i, a, nw)
          do p = 2, aord_num
            y = p * a_vector(p + 1, type_nucl_vector(a)) * x
            power_ser_g(ii) = power_ser_g(ii) + y * dx(ii)
            lap1 = lap1 + (p - 1) * y * xinv * dx(ii) * dx(ii)
            lap2 = lap2 + y
            x = x * en_distance_rescaled(i, a, nw)
          end do

          lap3 = lap3 - 2.0d0 * a_vector(2, type_nucl_vector(a)) * dx(ii) * dx(ii)

          factor_en_deriv_e(i, ii, nw) = factor_en_deriv_e(i, ii, nw) + a_vector(1, type_nucl_vector(a)) &
                                  ,* dx(ii) * invden2                                                        &
                                  + power_ser_g(ii)

        end do

        ii = 4
        lap2 = lap2 * dx(ii) * third
        lap3 = lap3 + den * dx(ii)
        lap3 = lap3 * a_vector(1, type_nucl_vector(a)) * invden3
        factor_en_deriv_e(i, ii, nw) = factor_en_deriv_e(i, ii, nw) + lap1 + lap2 + lap3

     end do
  end do
  end do

end function qmckl_compute_factor_en_deriv_e_f
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_en_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_en_deriv_e (
          const qmckl_context context,
          const int64_t walk_num,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t type_nucl_num,
          const int64_t* type_nucl_vector,
          const int64_t aord_num,
          const double* a_vector,
          const double* en_distance_rescaled,
          const double* en_distance_rescaled_deriv_e,
          double* const factor_en_deriv_e );
    #+end_src


    #+CALL: generate_c_interface(table=qmckl_factor_en_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_factor_en_deriv_e &
        (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         aord_num, &
         a_vector, &
         en_distance_rescaled, &
         en_distance_rescaled_deriv_e, &
         factor_en_deriv_e) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: type_nucl_num
      integer (c_int64_t) , intent(in)          :: type_nucl_vector(nucl_num)
      integer (c_int64_t) , intent(in)  , value :: aord_num
      real    (c_double ) , intent(in)          :: a_vector(type_nucl_num,aord_num+1)
      real    (c_double ) , intent(in)          :: en_distance_rescaled(elec_num,nucl_num,walk_num)
      real    (c_double ) , intent(in)          :: en_distance_rescaled_deriv_e(elec_num,nucl_num,4,walk_num)
      real    (c_double ) , intent(out)         :: factor_en_deriv_e(elec_num,4,walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_en_deriv_e_f
      info = qmckl_compute_factor_en_deriv_e_f &
             (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         aord_num, &
         a_vector, &
         en_distance_rescaled, &
         en_distance_rescaled_deriv_e, &
         factor_en_deriv_e)

    end function qmckl_compute_factor_en_deriv_e
    #+end_src

*** Test
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

kappa = 1.0

elec_coord = np.array(elec_coord)[0]
nucl_coord = np.array(nucl_coord)
elnuc_dist = np.zeros(shape=(elec_num, nucl_num),dtype=float)
for i in range(elec_num):
  for j in range(nucl_num):
    elnuc_dist[i, j] = np.linalg.norm(elec_coord[i] - nucl_coord[:,j])

elnuc_dist_deriv_e = np.zeros(shape=(4, elec_num, nucl_num),dtype=float)
for a in range(nucl_num):
  for i in range(elec_num):
    rij_inv = 1.0 / elnuc_dist[i, a]
    for ii in range(3):
      elnuc_dist_deriv_e[ii, i, a] = (elec_coord[i][ii] - nucl_coord[ii][a]) * rij_inv
    elnuc_dist_deriv_e[3, i, a] = 2.0 * rij_inv

en_distance_rescaled_deriv_e = np.zeros(shape=(4,elec_num,nucl_num),dtype=float)
for a in range(nucl_num):
  for i in range(elec_num):
    f = 1.0 - kappa * en_distance_rescaled[i][a]
    for ii in range(4):
      en_distance_rescaled_deriv_e[ii][i][a] = elnuc_dist_deriv_e[ii][i][a]
    en_distance_rescaled_deriv_e[3][i][a] = en_distance_rescaled_deriv_e[3][i][a] + \
                              (-kappa * en_distance_rescaled_deriv_e[0][i][a] * en_distance_rescaled_deriv_e[0][i][a]) + \
                              (-kappa * en_distance_rescaled_deriv_e[1][i][a] * en_distance_rescaled_deriv_e[1][i][a]) + \
                              (-kappa * en_distance_rescaled_deriv_e[2][i][a] * en_distance_rescaled_deriv_e[2][i][a])
    for ii in range(4):
      en_distance_rescaled_deriv_e[ii][i][a] = en_distance_rescaled_deriv_e[ii][i][a] * f

third = 1.0 / 3.0
factor_en_deriv_e = np.zeros(shape=(4,elec_num),dtype=float)
dx = np.zeros(shape=(4),dtype=float)
pow_ser_g = np.zeros(shape=(3),dtype=float)
for a in range(nucl_num):
   for i in range(elec_num):
      x = en_distance_rescaled[i][a]
      if abs(x) < 1e-18:
        continue
      pow_ser_g = np.zeros(shape=(3),dtype=float)
      den         = 1.0 + a_vector[1][type_nucl_vector[a]-1] * x
      invden      = 1.0 / den
      invden2     = invden * invden
      invden3     = invden2 * invden
      xinv        = 1.0 / (x + 1.0E-18)

      for ii in range(4):
        dx[ii] = en_distance_rescaled_deriv_e[ii][i][a]

      lap1 = 0.0
      lap2 = 0.0
      lap3 = 0.0
      for ii in range(3):
        x = en_distance_rescaled[i][a]
        if x < 1e-18:
          continue
        for p in range(2,aord_num+1):
          y = p * a_vector[(p-1) + 1][type_nucl_vector[a]-1] * x
          pow_ser_g[ii] = pow_ser_g[ii] + y * dx[ii]
          lap1 = lap1 + (p - 1) * y * xinv * dx[ii] * dx[ii]
          lap2 = lap2 + y
          x = x * en_distance_rescaled[i][a]

        lap3 = lap3 - 2.0 * a_vector[1][type_nucl_vector[a]-1] * dx[ii] * dx[ii]

        factor_en_deriv_e[ii][i] = factor_en_deriv_e[ii][i] + a_vector[0][type_nucl_vector[a]-1]  * \
                              dx[ii] * invden2 + pow_ser_g[ii]

      ii = 3
      lap2 = lap2 * dx[ii] * third
      lap3 = lap3 + den * dx[ii]
      lap3 = lap3 * (a_vector[0][type_nucl_vector[a]-1] * invden3)
      factor_en_deriv_e[ii][i] = factor_en_deriv_e[ii][i] + lap1 + lap2 + lap3

print("factor_en_deriv_e[0][0]:",factor_en_deriv_e[0][0])
print("factor_en_deriv_e[1][0]:",factor_en_deriv_e[1][0])
print("factor_en_deriv_e[2][0]:",factor_en_deriv_e[2][0])
print("factor_en_deriv_e[3][0]:",factor_en_deriv_e[3][0])


    #+end_src

    #+RESULTS:
    : factor_en_deriv_e[0][0]: 0.11609919541763383
    : factor_en_deriv_e[1][0]: -0.23301394780804574
    : factor_en_deriv_e[2][0]: 0.17548337641865783
    : factor_en_deriv_e[3][0]: -0.9667363412285741


     #+begin_src c :tangle (eval c_test)
/* Check if Jastrow is properly initialized */
assert(qmckl_jastrow_provided(context));

// calculate factor_en_deriv_e
double factor_en_deriv_e[walk_num][4][elec_num];
rc = qmckl_get_jastrow_factor_en_deriv_e(context, &(factor_en_deriv_e[0][0][0]),walk_num*4*elec_num);

// check factor_en_deriv_e
assert(fabs(factor_en_deriv_e[0][0][0]-0.11609919541763383) < 1.e-12);
assert(fabs(factor_en_deriv_e[0][1][0]+0.23301394780804574) < 1.e-12);
assert(fabs(factor_en_deriv_e[0][2][0]-0.17548337641865783) < 1.e-12);
assert(fabs(factor_en_deriv_e[0][3][0]+0.9667363412285741 ) < 1.e-12);

     #+end_src

** Electron-electron rescaled distances

   ~ee_distance_rescaled~ stores the matrix of the rescaled distances between all
   pairs of electrons:

   \[
   C_{ij} = \left( 1 - \exp{-\kappa C_{ij}}\right)/\kappa
   \]

  where \(C_{ij}\) is the matrix of electron-electron distances.

*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code qmckl_get_jastrow_ee_distance_rescaled(qmckl_context context, double* const distance_rescaled);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_get_jastrow_ee_distance_rescaled(qmckl_context context, double* const distance_rescaled)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_ee_distance_rescaled(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = ctx->electron.num * ctx->electron.num * ctx->electron.walker.num;
  memcpy(distance_rescaled, ctx->jastrow.ee_distance_rescaled, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_ee_distance_rescaled(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_ee_distance_rescaled(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);


  /* Compute if necessary */
  if (ctx->electron.walker.point.date > ctx->jastrow.ee_distance_rescaled_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.ee_distance_rescaled != NULL) {
        qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.ee_distance_rescaled);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_ee_distance_rescaled",
                                 "Unable to free ctx->jastrow.ee_distance_rescaled");
        }
        ctx->jastrow.ee_distance_rescaled = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.ee_distance_rescaled == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.num * ctx->electron.num *
        ctx->electron.walker.num * sizeof(double);
      double* ee_distance_rescaled = (double*) qmckl_malloc(context, mem_info);

      if (ee_distance_rescaled == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_ee_distance_rescaled",
                               NULL);
      }
      ctx->jastrow.ee_distance_rescaled = ee_distance_rescaled;
    }

    qmckl_exit_code rc =
      qmckl_compute_ee_distance_rescaled(context,
                                ctx->electron.num,
                                ctx->jastrow.rescale_factor_ee,
                                ctx->electron.walker.num,
                                ctx->electron.walker.point.coord.data,
                                ctx->jastrow.ee_distance_rescaled);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.ee_distance_rescaled_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_ee_distance_rescaled
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_ee_distance_rescaled_args
    | Variable            | Type                                   | In/Out | Description                          |
    |---------------------+----------------------------------------+--------+--------------------------------------|
    | ~context~           | ~qmckl_context~                        | in     | Global state                         |
    | ~elec_num~          | ~int64_t~                              | in     | Number of electrons                  |
    | ~rescale_factor_ee~ | ~double~                               | in     | Factor to rescale ee distances       |
    | ~walk_num~          | ~int64_t~                              | in     | Number of walkers                    |
    | ~coord~             | ~double[3][walk_num][elec_num]~        | in     | Electron coordinates                 |
    | ~ee_distance~       | ~double[walk_num][elec_num][elec_num]~ | out    | Electron-electron rescaled distances |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_ee_distance_rescaled_f(context, elec_num, rescale_factor_ee, walk_num, &
     coord, ee_distance_rescaled) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: elec_num
  double precision      , intent(in)  :: rescale_factor_ee
  integer*8             , intent(in)  :: walk_num
  double precision      , intent(in)  :: coord(elec_num,walk_num,3)
  double precision      , intent(out) :: ee_distance_rescaled(elec_num,elec_num,walk_num)

  integer*8 :: k

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  do k=1,walk_num
     info = qmckl_distance_rescaled(context, 'T', 'T', elec_num, elec_num, &
          coord(1,k,1), elec_num * walk_num, &
          coord(1,k,1), elec_num * walk_num, &
          ee_distance_rescaled(1,1,k), elec_num, rescale_factor_ee)
     if (info /= QMCKL_SUCCESS) then
        exit
     endif
  end do

end function qmckl_compute_ee_distance_rescaled_f
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org :exports none
qmckl_exit_code qmckl_compute_ee_distance_rescaled (
          const qmckl_context context,
          const int64_t elec_num,
          const double rescale_factor_ee,
          const int64_t walk_num,
          const double* coord,
          double* const ee_distance_rescaled );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_ee_distance_rescaled_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_ee_distance_rescaled &
        (context, elec_num, rescale_factor_ee, walk_num, coord, ee_distance_rescaled) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: elec_num
      real    (c_double ) , intent(in)  , value :: rescale_factor_ee
      integer (c_int64_t) , intent(in)  , value :: walk_num
      real    (c_double ) , intent(in)          :: coord(elec_num,3,walk_num)
      real    (c_double ) , intent(out)         :: ee_distance_rescaled(elec_num,elec_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_ee_distance_rescaled_f
      info = qmckl_compute_ee_distance_rescaled_f &
             (context, elec_num, rescale_factor_ee, walk_num, coord, ee_distance_rescaled)

    end function qmckl_compute_ee_distance_rescaled
    #+end_src

*** Test

    #+begin_src python :results output :exports none
import numpy as np

kappa = 1.0

elec_1_w1 = np.array( [-0.250655104764153,  0.503070975550133      ,  -0.166554344502303])
elec_2_w1 = np.array( [-0.587812193472177, -0.128751981129274      ,   0.187773606533075])
elec_5_w1 = np.array( [-0.127732483187947, -0.138975497694196      ,  -8.669850480215846E-002])
elec_6_w1 = np.array( [-0.232271834949124, -1.059321673434182E-002 ,  -0.504862241464867])

print ( "[0][0] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_1_w1-elec_1_w1)) )/kappa )
print ( "[0][1] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_1_w1-elec_2_w1)) )/kappa )
print ( "[1][0] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_2_w1-elec_1_w1)) )/kappa )
print ( "[5][5] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_5_w1-elec_5_w1)) )/kappa )
print ( "[5][6] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_5_w1-elec_6_w1)) )/kappa )
print ( "[6][5] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_6_w1-elec_5_w1)) )/kappa )
    #+end_src

    #+RESULTS:
    : [0][0] :  0.0
    : [0][1] :  0.5502278003524018
    : [1][0] :  0.5502278003524018
    : [5][5] :  0.0
    : [5][6] :  0.3622098222364193
    : [6][5] :  0.3622098222364193

     #+begin_src c :tangle (eval c_test)
assert(qmckl_electron_provided(context));


double ee_distance_rescaled[walk_num * elec_num * elec_num];
rc = qmckl_get_jastrow_ee_distance_rescaled(context, ee_distance_rescaled);

// (e1,e2,w)
// (0,0,0) == 0.
assert(ee_distance_rescaled[0] == 0.);

// (1,0,0) == (0,1,0)
assert(ee_distance_rescaled[1] == ee_distance_rescaled[elec_num]);

// value of (1,0,0)
assert(fabs(ee_distance_rescaled[1]-0.5502278003524018) < 1.e-12);

// (0,0,1) == 0.
assert(ee_distance_rescaled[5*elec_num + 5] == 0.);

// (1,0,1) == (0,1,1)
assert(ee_distance_rescaled[5*elec_num+6] == ee_distance_rescaled[6*elec_num+5]);

// value of (1,0,1)
assert(fabs(ee_distance_rescaled[5*elec_num+6]-0.3622098222364193) < 1.e-12);

     #+end_src

** Electron-electron rescaled distance gradients and Laplacian with respect to electron coords

  The rescaled distances which is given as $R = (1 - \exp{-\kappa r})/\kappa$
  needs to be perturbed with respect to the electorn coordinates.
  This data is stored in the ~ee_distance_rescaled_deriv_e~ tensor. The
  The first three elements of this three index tensor ~[4][num][num]~ gives the
  derivatives in the x, y, and z directions $dx, dy, dz$ and the last index
  gives the Laplacian $\partial x^2 + \partial y^2 + \partial z^2$.

*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code qmckl_get_jastrow_ee_distance_rescaled_deriv_e(qmckl_context context, double* const distance_rescaled_deriv_e);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_get_jastrow_ee_distance_rescaled_deriv_e(qmckl_context context, double* const distance_rescaled_deriv_e)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_ee_distance_rescaled_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = 4 * ctx->electron.num * ctx->electron.num * ctx->electron.walker.num;
  memcpy(distance_rescaled_deriv_e, ctx->jastrow.ee_distance_rescaled_deriv_e, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_ee_distance_rescaled_deriv_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_ee_distance_rescaled_deriv_e(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);


  /* Compute if necessary */
  if (ctx->electron.walker.point.date > ctx->jastrow.ee_distance_rescaled_deriv_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.ee_distance_rescaled_deriv_e != NULL) {
        qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.ee_distance_rescaled_deriv_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_ee_distance_rescaled_deriv_e",
                                 "Unable to free ctx->jastrow.ee_distance_rescaled_deriv_e");
        }
        ctx->jastrow.ee_distance_rescaled_deriv_e = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.ee_distance_rescaled_deriv_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = 4 * ctx->electron.num * ctx->electron.num *
        ctx->electron.walker.num * sizeof(double);
      double* ee_distance_rescaled_deriv_e = (double*) qmckl_malloc(context, mem_info);

      if (ee_distance_rescaled_deriv_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_ee_distance_rescaled_deriv_e",
                               NULL);
      }
      ctx->jastrow.ee_distance_rescaled_deriv_e = ee_distance_rescaled_deriv_e;
    }

    qmckl_exit_code rc =
      qmckl_compute_ee_distance_rescaled_deriv_e(context,
                                ctx->electron.num,
                                ctx->jastrow.rescale_factor_ee,
                                ctx->electron.walker.num,
                                ctx->electron.walker.point.coord.data,
                                ctx->jastrow.ee_distance_rescaled_deriv_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.ee_distance_rescaled_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_ee_distance_rescaled_deriv_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_ee_distance_rescaled_deriv_e_args
    | Variable              | Type                                      | In/Out | Description                                     |
    |-----------------------+-------------------------------------------+--------+-------------------------------------------------|
    | ~context~             | ~qmckl_context~                           | in     | Global state                                    |
    | ~elec_num~            | ~int64_t~                                 | in     | Number of electrons                             |
    | ~rescale_factor_ee~   | ~double~                                  | in     | Factor to rescale ee distances                  |
    | ~walk_num~            | ~int64_t~                                 | in     | Number of walkers                               |
    | ~coord~               | ~double[3][walk_num][elec_num]~           | in     | Electron coordinates                            |
    | ~ee_distance_deriv_e~ | ~double[walk_num][4][elec_num][elec_num]~ | out    | Electron-electron rescaled distance derivatives |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_ee_distance_rescaled_deriv_e_f(context, elec_num, rescale_factor_ee, walk_num, &
     coord, ee_distance_rescaled_deriv_e) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: elec_num
  double precision      , intent(in)  :: rescale_factor_ee
  integer*8             , intent(in)  :: walk_num
  double precision      , intent(in)  :: coord(elec_num,walk_num,3)
  double precision      , intent(out) :: ee_distance_rescaled_deriv_e(4,elec_num,elec_num,walk_num)

  integer*8 :: k

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  do k=1,walk_num
     info = qmckl_distance_rescaled_deriv_e(context, 'T', 'T', elec_num, elec_num, &
          coord(1,k,1), elec_num*walk_num, &
          coord(1,k,1), elec_num*walk_num, &
          ee_distance_rescaled_deriv_e(1,1,1,k), elec_num, rescale_factor_ee)
     if (info /= QMCKL_SUCCESS) then
        exit
     endif
  end do

end function qmckl_compute_ee_distance_rescaled_deriv_e_f
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org :exports none
qmckl_exit_code qmckl_compute_ee_distance_rescaled_deriv_e (
          const qmckl_context context,
          const int64_t elec_num,
          const double rescale_factor_ee,
          const int64_t walk_num,
          const double* coord,
          double* const ee_distance_rescaled_deriv_e );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_ee_distance_rescaled_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_ee_distance_rescaled_deriv_e &
        (context, elec_num, rescale_factor_ee, walk_num, coord, ee_distance_rescaled_deriv_e) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: elec_num
      real    (c_double ) , intent(in)  , value :: rescale_factor_ee
      integer (c_int64_t) , intent(in)  , value :: walk_num
      real    (c_double ) , intent(in)          :: coord(elec_num,3,walk_num)
      real    (c_double ) , intent(out)         :: ee_distance_rescaled_deriv_e(4,elec_num,elec_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_ee_distance_rescaled_deriv_e_f
      info = qmckl_compute_ee_distance_rescaled_deriv_e_f &
             (context, elec_num, rescale_factor_ee, walk_num, coord, ee_distance_rescaled_deriv_e)

    end function qmckl_compute_ee_distance_rescaled_deriv_e
    #+end_src

*** Test

    #+begin_src python :results output :exports none
import numpy as np

# TODO
    #+end_src

     #+begin_src c :tangle (eval c_test)
assert(qmckl_electron_provided(context));


double ee_distance_rescaled_deriv_e[4 * walk_num * elec_num * elec_num];
rc = qmckl_get_jastrow_ee_distance_rescaled_deriv_e(context, ee_distance_rescaled_deriv_e);

// TODO: Get exact values
//// (e1,e2,w)
//// (0,0,0) == 0.
//assert(ee_distance[0] == 0.);
//
//// (1,0,0) == (0,1,0)
//assert(ee_distance[1] == ee_distance[elec_num]);
//
//// value of (1,0,0)
//assert(fabs(ee_distance[1]-7.152322512964209) < 1.e-12);
//
//// (0,0,1) == 0.
//assert(ee_distance[elec_num*elec_num] == 0.);
//
//// (1,0,1) == (0,1,1)
//assert(ee_distance[elec_num*elec_num+1] == ee_distance[elec_num*elec_num+elec_num]);
//
//// value of (1,0,1)
//assert(fabs(ee_distance[elec_num*elec_num+1]-6.5517646321055665) < 1.e-12);

     #+end_src

** Electron-electron-nucleus rescaled distances for each order

   ~een_rescaled_e~ stores the table of the rescaled distances between all
   pairs of electrons and raised to the power \(p\) defined by ~cord_num~:

   \[
   C_{ij,p} = \left( 1 - \exp{-\kappa C_{ij}} \right)^p
   \]

  where \(C_{ij}\) is the matrix of electron-electron distances.

*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_e(qmckl_context context,
                                 double* const distance_rescaled,
                                 const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_e(qmckl_context context,
                                 double* const distance_rescaled,
                                 const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_een_rescaled_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * ctx->electron.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1);
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_een_rescaled_e",
                           "Array too small. Expected ctx->electron.num * ctx->electron.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1)");
  }
  memcpy(distance_rescaled, ctx->jastrow.een_rescaled_e, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_een_rescaled_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_een_rescaled_e(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Check if ee distance is provided */
  qmckl_exit_code rc = qmckl_provide_ee_distance(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.een_rescaled_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.een_rescaled_e != NULL) {
        rc = qmckl_free(context, ctx->jastrow.een_rescaled_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_een_rescaled_e",
                                 "Unable to free ctx->jastrow.een_rescaled_e");
        }
        ctx->jastrow.een_rescaled_e = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.een_rescaled_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.num * ctx->electron.num *
        ctx->electron.walker.num * (ctx->jastrow.cord_num + 1) * sizeof(double);
      double* een_rescaled_e = (double*) qmckl_malloc(context, mem_info);

      if (een_rescaled_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_een_rescaled_e",
                               NULL);
      }
      ctx->jastrow.een_rescaled_e = een_rescaled_e;
    }

    rc = qmckl_compute_een_rescaled_e(context,
                                      ctx->electron.walker.num,
                                      ctx->electron.num,
                                      ctx->jastrow.cord_num,
                                      ctx->jastrow.rescale_factor_ee,
                                      ctx->electron.ee_distance,
                                      ctx->jastrow.een_rescaled_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.een_rescaled_e_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_een_rescaled_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_een_rescaled_e_args
    | Variable            | Type                                               | In/Out | Description                          |
    |---------------------+----------------------------------------------------+--------+--------------------------------------|
    | ~context~           | ~qmckl_context~                                    | in     | Global state                         |
    | ~walk_num~          | ~int64_t~                                          | in     | Number of walkers                    |
    | ~elec_num~          | ~int64_t~                                          | in     | Number of electrons                  |
    | ~cord_num~          | ~int64_t~                                          | in     | Order of polynomials                 |
    | ~rescale_factor_ee~ | ~double~                                           | in     | Factor to rescale ee distances       |
    | ~ee_distance~       | ~double[walk_num][elec_num][elec_num]~             | in     | Electron-electron distances          |
    | ~een_rescaled_e~    | ~double[walk_num][0:cord_num][elec_num][elec_num]~ | out    | Electron-electron rescaled distances |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_een_rescaled_e_doc_f( &
     context, walk_num, elec_num, cord_num, rescale_factor_ee,  &
     ee_distance, een_rescaled_e) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: cord_num
  double precision      , intent(in)  :: rescale_factor_ee
  double precision      , intent(in)  :: ee_distance(elec_num,elec_num,walk_num)
  double precision      , intent(out) :: een_rescaled_e(elec_num,elec_num,0:cord_num,walk_num)
  double precision,dimension(:,:),allocatable :: een_rescaled_e_ij
  double precision                    :: x
  integer*8                           :: i, j, k, l, nw

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  allocate(een_rescaled_e_ij(elec_num * (elec_num - 1) / 2, cord_num + 1))

  ! Prepare table of exponentiated distances raised to appropriate power
  een_rescaled_e             = 0.0d0
  do nw = 1, walk_num
  een_rescaled_e_ij       = 0.0d0
  een_rescaled_e_ij(:, 1) = 1.0d0


  k = 0
  do j = 1, elec_num
    do i = 1, j - 1
      k = k + 1
      een_rescaled_e_ij(k, 2) = dexp(-rescale_factor_ee * ee_distance(i, j, nw))
    end do
  end do


  do l = 2, cord_num
    do k = 1, elec_num * (elec_num - 1)/2
      een_rescaled_e_ij(k, l + 1) = een_rescaled_e_ij(k, l + 1 - 1) * een_rescaled_e_ij(k, 2)
    end do
  end do

  ! prepare the actual een table
  een_rescaled_e(:, :, 0, nw) = 1.0d0

  do l = 1, cord_num
    k = 0
    do j = 1, elec_num
      do i = 1, j - 1
        k = k + 1
        x = een_rescaled_e_ij(k, l + 1)
        een_rescaled_e(i, j, l, nw) = x
        een_rescaled_e(j, i, l, nw) = x
      end do
    end do
  end do

  do l = 0, cord_num
    do j = 1, elec_num
      een_rescaled_e(j, j, l, nw) = 0.0d0
    end do
  end do

  end do

end function qmckl_compute_een_rescaled_e_doc_f
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_een_rescaled_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_een_rescaled_e (
          const qmckl_context context,
          const int64_t walk_num,
          const int64_t elec_num,
          const int64_t cord_num,
          const double rescale_factor_ee,
          const double* ee_distance,
          double* const een_rescaled_e );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_factor_een_rescaled_e_args,rettyp=get_value("CRetType"),fname="qmckl_compute_een_rescaled_e_doc")

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_een_rescaled_e_doc &
	(context, walk_num, elec_num, cord_num, rescale_factor_ee, &
        ee_distance, een_rescaled_e) &
    bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: cord_num
      real    (c_double ) , intent(in)  , value :: rescale_factor_ee
      real    (c_double ) , intent(in)          :: ee_distance(elec_num,elec_num,walk_num)
      real    (c_double ) , intent(out)         :: een_rescaled_e(elec_num,elec_num,0:cord_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_een_rescaled_e_doc_f
      info = qmckl_compute_een_rescaled_e_doc_f &
	     (context, walk_num, elec_num, cord_num, rescale_factor_ee, ee_distance, een_rescaled_e)

    end function qmckl_compute_een_rescaled_e_doc
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_een_rescaled_e_hpc (
	  const qmckl_context context,
	  const int64_t walk_num,
	  const int64_t elec_num,
	  const int64_t cord_num,
	  const double rescale_factor_ee,
	  const double* ee_distance,
	  double* const een_rescaled_e ) {

  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (walk_num <= 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
     return QMCKL_INVALID_ARG_3;
  }

  if (cord_num < 0) {
     return QMCKL_INVALID_ARG_4;
  }

  // Prepare table of exponentiated distances raised to appropriate power
  // init

  for (int kk = 0; kk < walk_num*(cord_num+1)*elec_num*elec_num; ++kk) {
    een_rescaled_e[kk]= 0.0;
  }

  double   x;
  const int64_t   elec_pairs = (elec_num * (elec_num - 1)) / 2;
  const int64_t   len_een_ij = elec_pairs * (cord_num + 1);

  // number of elements for the een_rescaled_e_ij[N_e*(N_e-1)/2][cord+1]
  // probably in C is better [cord+1, Ne*(Ne-1)/2]
  // elec_pairs = (elec_num * (elec_num - 1)) / 2;
  // len_een_ij = elec_pairs * (cord_num + 1);
  double* een_rescaled_e_ij = (double *) malloc (len_een_ij * sizeof(double));
  if (een_rescaled_e_ij == NULL) {
    return qmckl_failwith( context,
                           QMCKL_ALLOCATION_FAILED,
                           "qmckl_compute_een_rescaled_e_hpc",
                           NULL);
  }

  /*
  for (int nw = 0; nw < walk_num; ++nw) {
    for (int l = 0; l < (cord_num + 1); ++l) {
      for (int i = 0; i < elec_num; ++i) {
        for (int j = 0; j < elec_num; ++j) {
          een_rescaled_e[j + i*elec_num + l*elec_num*elec_num + nw*(cord_num+1)*elec_num*elec_num]= 0.0;
        }
      }
    }
  }
  */

  for (int nw = 0; nw < walk_num; ++nw) {

    for (int kk = 0; kk < len_een_ij; ++kk) {
      // this array initialized at 0 except een_rescaled_e_ij(:, 1) = 1.0d0
      // and the arrangement of indices is [cord_num+1, ne*(ne-1)/2]
      een_rescaled_e_ij[kk]= ( kk < (elec_pairs) ? 1.0 : 0.0 );
    }

    int64_t kk = 0;
    for (int i = 0; i < elec_num; ++i) {
      for (int j = 0; j < i; ++j) {
        // een_rescaled_e_ij(kk, 2) = dexp(-rescale_factor_ee * ee_distance(i, j, nw));
        een_rescaled_e_ij[kk + elec_pairs] = exp(-rescale_factor_ee * \
                                    ee_distance[j + i*elec_num + nw*(elec_num*elec_num)]);
        kk += 1;
      }
    }


    for (int l = 2; l < (cord_num+1); ++l) {
      for (int k = 0; k < elec_pairs; ++k) {
      // een_rescaled_e_ij(k, l + 1) = een_rescaled_e_ij(k, l + 1 - 1) * een_rescaled_e_ij(k, 2)
        een_rescaled_e_ij[k+l*elec_pairs] = een_rescaled_e_ij[k + (l - 1)*elec_pairs] * \
                                                  een_rescaled_e_ij[k + elec_pairs];
      }
    }


  // prepare the actual een table
  for (int i = 0; i < elec_num; ++i){
    for (int j = 0; j < elec_num; ++j) {
      een_rescaled_e[j + i*elec_num + 0 + nw*(cord_num+1)*elec_num*elec_num] = 1.0;
    }
  }

    // Up to here it should work.
  for ( int l = 1; l < (cord_num+1); ++l) {
    int k = 0;
    for (int i = 0; i < elec_num; ++i) {
      for (int j = 0; j < i; ++j) {
        x = een_rescaled_e_ij[k + l*elec_pairs];
        een_rescaled_e[j + i*elec_num + l*elec_num*elec_num + nw*elec_num*elec_num*(cord_num+1)] = x;
        een_rescaled_e[i + j*elec_num + l*elec_num*elec_num + nw*elec_num*elec_num*(cord_num+1)] = x;
        k = k + 1;
      }
    }
  }

  for (int l = 0; l < (cord_num + 1); ++l) {
    for (int j = 0; j < elec_num; ++j) {
      een_rescaled_e[j + j*elec_num + l*elec_num*elec_num + nw*elec_num*elec_num*(cord_num+1)] = 0.0;
    }
  }

  }

  free(een_rescaled_e_ij);

  return QMCKL_SUCCESS;
}
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_een_rescaled_e_args,rettyp=get_value("CRetType"),fname="qmckl_compute_een_rescaled_e_doc")

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_een_rescaled_e (
	  const qmckl_context context,
	  const int64_t walk_num,
	  const int64_t elec_num,
	  const int64_t cord_num,
	  const double rescale_factor_ee,
	  const double* ee_distance,
	  double* const een_rescaled_e );
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org
    qmckl_exit_code qmckl_compute_een_rescaled_e_doc (
	  const qmckl_context context,
	  const int64_t walk_num,
	  const int64_t elec_num,
	  const int64_t cord_num,
	  const double rescale_factor_ee,
	  const double* ee_distance,
	  double* const een_rescaled_e );
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org
    qmckl_exit_code qmckl_compute_een_rescaled_e_hpc (
	  const qmckl_context context,
	  const int64_t walk_num,
	  const int64_t elec_num,
	  const int64_t cord_num,
	  const double rescale_factor_ee,
	  const double* ee_distance,
	  double* const een_rescaled_e );
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
    qmckl_exit_code qmckl_compute_een_rescaled_e (
	  const qmckl_context context,
	  const int64_t walk_num,
	  const int64_t elec_num,
	  const int64_t cord_num,
	  const double rescale_factor_ee,
	  const double* ee_distance,
	  double* const een_rescaled_e ) {

    #ifdef HAVE_HPC
    return qmckl_compute_een_rescaled_e_hpc(context, walk_num, elec_num, cord_num, rescale_factor_ee, ee_distance, een_rescaled_e);
    #else
    return qmckl_compute_een_rescaled_e_doc(context, walk_num, elec_num, cord_num, rescale_factor_ee, ee_distance, een_rescaled_e);
    #endif
    }
    #+end_src


*** Test

    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

elec_coord = np.array(elec_coord)[0]
elec_dist = np.zeros(shape=(elec_num, elec_num),dtype=float)
for i in range(elec_num):
  for j in range(elec_num):
    elec_dist[i, j] = np.linalg.norm(elec_coord[i] - elec_coord[j])

kappa = 1.0

een_rescaled_e_ij = np.zeros(shape=(elec_num * (elec_num - 1)//2, cord_num+1), dtype=float)
een_rescaled_e_ij[:,0] = 1.0

k = 0
for j in range(elec_num):
  for i in range(j):
    een_rescaled_e_ij[k, 1] = np.exp(-kappa * elec_dist[i, j])
    k = k + 1

for l in range(2, cord_num + 1):
  for k in range(elec_num * (elec_num - 1)//2):
    een_rescaled_e_ij[k, l] = een_rescaled_e_ij[k, l - 1] * een_rescaled_e_ij[k, 1]

een_rescaled_e = np.zeros(shape=(elec_num, elec_num, cord_num + 1), dtype=float)
een_rescaled_e[:,:,0] = 1.0

for l in range(1,cord_num+1):
  k = 0
  for j in range(elec_num):
    for i in range(j):
      x = een_rescaled_e_ij[k, l]
      een_rescaled_e[i, j, l] = x
      een_rescaled_e[j, i, l] = x
      k = k + 1

for l in range(0,cord_num+1):
  for j in range(0, elec_num):
    een_rescaled_e[j,j,l] = 0.0

print(" een_rescaled_e[0, 2, 1] = ",een_rescaled_e[0, 2, 1])
print(" een_rescaled_e[0, 3, 1] = ",een_rescaled_e[0, 3, 1])
print(" een_rescaled_e[0, 4, 1] = ",een_rescaled_e[0, 4, 1])
print(" een_rescaled_e[1, 3, 2] = ",een_rescaled_e[1, 3, 2])
print(" een_rescaled_e[1, 4, 2] = ",een_rescaled_e[1, 4, 2])
print(" een_rescaled_e[1, 5, 2] = ",een_rescaled_e[1, 5, 2])
    #+end_src

    #+RESULTS:
    :  een_rescaled_e[0, 2, 1] =  0.08084493981483197
    :  een_rescaled_e[0, 3, 1] =  0.1066745707571846
    :  een_rescaled_e[0, 4, 1] =  0.017542731694647366
    :  een_rescaled_e[1, 3, 2] =  0.02214680362033448
    :  een_rescaled_e[1, 4, 2] =  0.0005700154999202759
    :  een_rescaled_e[1, 5, 2] =  0.3424402276009091

     #+begin_src c :tangle (eval c_test)
assert(qmckl_electron_provided(context));


double een_rescaled_e[walk_num][(cord_num + 1)][elec_num][elec_num];
rc = qmckl_get_jastrow_een_rescaled_e(context, &(een_rescaled_e[0][0][0][0]),elec_num*elec_num*(cord_num+1)*walk_num);

// value of (0,2,1)
assert(fabs(een_rescaled_e[0][1][0][2]-0.08084493981483197)   < 1.e-12);
assert(fabs(een_rescaled_e[0][1][0][3]-0.1066745707571846)    < 1.e-12);
assert(fabs(een_rescaled_e[0][1][0][4]-0.01754273169464735)   < 1.e-12);
assert(fabs(een_rescaled_e[0][2][1][3]-0.02214680362033448)   < 1.e-12);
assert(fabs(een_rescaled_e[0][2][1][4]-0.0005700154999202759) < 1.e-12);
assert(fabs(een_rescaled_e[0][2][1][5]-0.3424402276009091)    < 1.e-12);
     #+end_src

** Electron-electron-nucleus rescaled distances for each order and derivatives

   ~een_rescaled_e_deriv_e~ stores the table of the derivatives of the
   rescaled distances between all pairs of electrons and raised to the
   power \(p\) defined by ~cord_num~.  Here we take its derivatives
   required for the een jastrow.

   TODO: write formulae


*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_e_deriv_e(qmckl_context context,
                                         double* const distance_rescaled,
                                         const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_e_deriv_e(qmckl_context context,
                                         double* const distance_rescaled,
                                         const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_een_rescaled_e_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * 4 * ctx->electron.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1);
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_een_deriv_e",
                           "Array too small. Expected ctx->electron.num * 4 * ctx->electron.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1)");
  }
  memcpy(distance_rescaled, ctx->jastrow.een_rescaled_e_deriv_e, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_een_rescaled_e_deriv_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_een_rescaled_e_deriv_e(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Check if ee distance is provided */
  qmckl_exit_code rc = qmckl_provide_een_rescaled_e(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.een_rescaled_e_deriv_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.een_rescaled_e_deriv_e != NULL) {
        rc = qmckl_free(context, ctx->jastrow.een_rescaled_e_deriv_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_een_rescaled_e_deriv_e",
                                 "Unable to free ctx->jastrow.een_rescaled_e_deriv_e");
        }
        ctx->jastrow.een_rescaled_e_deriv_e = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.een_rescaled_e_deriv_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.num * 4 * ctx->electron.num *
        ctx->electron.walker.num * (ctx->jastrow.cord_num + 1) * sizeof(double);
      double* een_rescaled_e_deriv_e = (double*) qmckl_malloc(context, mem_info);

      if (een_rescaled_e_deriv_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_een_rescaled_e_deriv_e",
                               NULL);
      }
      ctx->jastrow.een_rescaled_e_deriv_e = een_rescaled_e_deriv_e;
    }

    rc = qmckl_compute_factor_een_rescaled_e_deriv_e(context,
                                                     ctx->electron.walker.num,
                                                     ctx->electron.num,
                                                     ctx->jastrow.cord_num,
                                                     ctx->jastrow.rescale_factor_ee,
                                                     ctx->electron.walker.point.coord.data,
                                                     ctx->electron.ee_distance,
                                                     ctx->jastrow.een_rescaled_e,
                                                     ctx->jastrow.een_rescaled_e_deriv_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.een_rescaled_e_deriv_e_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_een_rescaled_e_deriv_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_een_rescaled_e_deriv_e_args
    | Variable                 | Type                                                  | In/Out | Description                          |
    |--------------------------+-------------------------------------------------------+--------+--------------------------------------|
    | ~context~                | ~qmckl_context~                                       | in     | Global state                         |
    | ~walk_num~               | ~int64_t~                                             | in     | Number of walkers                    |
    | ~elec_num~               | ~int64_t~                                             | in     | Number of electrons                  |
    | ~cord_num~               | ~int64_t~                                             | in     | Order of polynomials                 |
    | ~rescale_factor_ee~      | ~double~                                              | in     | Factor to rescale ee distances       |
    | ~coord_ee~               | ~double[walk_num][3][elec_num]~                       | in     | Electron coordinates                 |
    | ~ee_distance~            | ~double[walk_num][elec_num][elec_num]~                | in     | Electron-electron distances          |
    | ~een_rescaled_e~         | ~double[walk_num][0:cord_num][elec_num][elec_num]~    | in     | Electron-electron distances          |
    | ~een_rescaled_e_deriv_e~ | ~double[walk_num][0:cord_num][elec_num][4][elec_num]~ | out    | Electron-electron rescaled distances |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_een_rescaled_e_deriv_e_f( &
     context, walk_num, elec_num, cord_num, rescale_factor_ee,  &
     coord_ee, ee_distance, een_rescaled_e, een_rescaled_e_deriv_e) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: cord_num
  double precision      , intent(in)  :: rescale_factor_ee
  double precision      , intent(in)  :: coord_ee(elec_num,3,walk_num)
  double precision      , intent(in)  :: ee_distance(elec_num,elec_num,walk_num)
  double precision      , intent(in)  :: een_rescaled_e(elec_num,elec_num,0:cord_num,walk_num)
  double precision      , intent(out) :: een_rescaled_e_deriv_e(elec_num,4,elec_num,0:cord_num,walk_num)
  double precision,dimension(:,:,:),allocatable  :: elec_dist_deriv_e
  double precision                    :: x, rij_inv, kappa_l
  integer*8                           :: i, j, k, l, nw, ii

  allocate(elec_dist_deriv_e(4,elec_num,elec_num))

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  ! Prepare table of exponentiated distances raised to appropriate power
  een_rescaled_e_deriv_e     = 0.0d0
  do nw = 1, walk_num
    do j = 1, elec_num
      do i = 1, elec_num
        rij_inv = 1.0d0 / ee_distance(i, j, nw)
        do ii = 1, 3
          elec_dist_deriv_e(ii, i, j) = (coord_ee(i, ii, nw) - coord_ee(j, ii, nw)) * rij_inv
        end do
        elec_dist_deriv_e(4, i, j) = 2.0d0 * rij_inv
      end do
      elec_dist_deriv_e(:, j, j) = 0.0d0
    end do

    ! prepare the actual een table
    do l = 1, cord_num
      kappa_l = - dble(l) * rescale_factor_ee
      do j = 1, elec_num
        do i = 1, elec_num
          een_rescaled_e_deriv_e(i, 1, j, l, nw) = kappa_l * elec_dist_deriv_e(1, i, j)
          een_rescaled_e_deriv_e(i, 2, j, l, nw) = kappa_l * elec_dist_deriv_e(2, i, j)
          een_rescaled_e_deriv_e(i, 3, j, l, nw) = kappa_l * elec_dist_deriv_e(3, i, j)
          een_rescaled_e_deriv_e(i, 4, j, l, nw) = kappa_l * elec_dist_deriv_e(4, i, j)

          een_rescaled_e_deriv_e(i, 4, j, l, nw) = een_rescaled_e_deriv_e(i, 4, j, l, nw)              &
                    + een_rescaled_e_deriv_e(i, 1, j, l, nw) * een_rescaled_e_deriv_e(i, 1, j, l, nw)  &
                    + een_rescaled_e_deriv_e(i, 2, j, l, nw) * een_rescaled_e_deriv_e(i, 2, j, l, nw)  &
                    + een_rescaled_e_deriv_e(i, 3, j, l, nw) * een_rescaled_e_deriv_e(i, 3, j, l, nw)

          een_rescaled_e_deriv_e(i, 1, j, l, nw) = een_rescaled_e_deriv_e(i, 1, j, l, nw) *   &
                                                    een_rescaled_e(i, j, l, nw)
          een_rescaled_e_deriv_e(i, 3, j, l, nw) = een_rescaled_e_deriv_e(i, 2, j, l, nw) *   &
                                                    een_rescaled_e(i, j, l, nw)
          een_rescaled_e_deriv_e(i, 3, j, l, nw) = een_rescaled_e_deriv_e(i, 3, j, l, nw) *   &
                                                    een_rescaled_e(i, j, l, nw)
          een_rescaled_e_deriv_e(i, 4, j, l, nw) = een_rescaled_e_deriv_e(i, 4, j, l, nw) *   &
                                                    een_rescaled_e(i, j, l, nw)
        end do
      end do
    end do
  end do

end function qmckl_compute_factor_een_rescaled_e_deriv_e_f
    #+end_src

#  #+CALL: generate_c_header(table=qmckl_factor_een_rescaled_e_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
   qmckl_exit_code qmckl_compute_factor_een_rescaled_e_deriv_e (
         const qmckl_context context,
         const int64_t walk_num,
         const int64_t elec_num,
         const int64_t cord_num,
         const double rescale_factor_ee,
         const double* coord_ee,
         const double* ee_distance,
         const double* een_rescaled_e,
         double* const een_rescaled_e_deriv_e );
   #+end_src


    #+CALL: generate_c_interface(table=qmckl_factor_een_rescaled_e_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_factor_een_rescaled_e_deriv_e &
        (context, &
         walk_num, &
         elec_num, &
         cord_num, &
         rescale_factor_ee, &
         coord_ee, &
         ee_distance, &
         een_rescaled_e, &
         een_rescaled_e_deriv_e) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: cord_num
      real    (c_double ) , intent(in)  , value :: rescale_factor_ee
      real    (c_double ) , intent(in)          :: coord_ee(elec_num,3,walk_num)
      real    (c_double ) , intent(in)          :: ee_distance(elec_num,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_e(elec_num,elec_num,0:cord_num,walk_num)
      real    (c_double ) , intent(out)         :: een_rescaled_e_deriv_e(elec_num,4,elec_num,0:cord_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_een_rescaled_e_deriv_e_f
      info = qmckl_compute_factor_een_rescaled_e_deriv_e_f &
             (context, &
         walk_num, &
         elec_num, &
         cord_num, &
         rescale_factor_ee, &
         coord_ee, &
         ee_distance, &
         een_rescaled_e, &
         een_rescaled_e_deriv_e)

    end function qmckl_compute_factor_een_rescaled_e_deriv_e
    #+end_src

*** Test
#+name: een_e_deriv_e
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

elec_coord = np.array(elec_coord)[0]
elec_dist = np.zeros(shape=(elec_num, elec_num),dtype=float)
for i in range(elec_num):
  for j in range(elec_num):
    elec_dist[i, j] = np.linalg.norm(elec_coord[i] - elec_coord[j])

elec_dist_deriv_e = np.zeros(shape=(4,elec_num, elec_num),dtype=float)
for j in range(elec_num):
  for i in range(elec_num):
    rij_inv = 1.0 / elec_dist[i, j]
    for ii in range(3):
      elec_dist_deriv_e[ii, i, j] = -(elec_coord[j][ii] - elec_coord[i][ii]) * rij_inv
    elec_dist_deriv_e[3, i, j] = 2.0 * rij_inv
  elec_dist_deriv_e[:, j, j] = 0.0


kappa = 1.0

een_rescaled_e_ij = np.zeros(shape=(elec_num * (elec_num - 1)//2, cord_num+1), dtype=float)
een_rescaled_e_ij[:,0] = 1.0

k = 0
for j in range(elec_num):
  for i in range(j):
    een_rescaled_e_ij[k, 1] = np.exp(-kappa * elec_dist[i, j])
    k = k + 1

for l in range(2, cord_num + 1):
  for k in range(elec_num * (elec_num - 1)//2):
    een_rescaled_e_ij[k, l] = een_rescaled_e_ij[k, l - 1] * een_rescaled_e_ij[k, 1]

een_rescaled_e = np.zeros(shape=(elec_num, elec_num, cord_num + 1), dtype=float)
een_rescaled_e[:,:,0] = 1.0

for l in range(1,cord_num+1):
  k = 0
  for j in range(elec_num):
    for i in range(j):
      x = een_rescaled_e_ij[k, l]
      een_rescaled_e[i, j, l] = x
      een_rescaled_e[j, i, l] = x
      k = k + 1

een_rescaled_e_deriv_e = np.zeros(shape=(elec_num,4,elec_num,cord_num+1),dtype=float)
for l in range(0,cord_num+1):
  kappa_l = -1.0 * kappa * l
  for j in range(0,elec_num):
    for i in range(0,elec_num):
      for ii in range(0,4):
        een_rescaled_e_deriv_e[i,ii,j,l] = kappa_l * elec_dist_deriv_e[ii,i,j]
      een_rescaled_e_deriv_e[i,3,j,l] = een_rescaled_e_deriv_e[i,3,j,l] +        \
      een_rescaled_e_deriv_e[i,0,j,l] * een_rescaled_e_deriv_e[i,0,j,l] +        \
      een_rescaled_e_deriv_e[i,1,j,l] * een_rescaled_e_deriv_e[i,1,j,l] +        \
      een_rescaled_e_deriv_e[i,2,j,l] * een_rescaled_e_deriv_e[i,2,j,l]

      for ii in range(0,4):
        een_rescaled_e_deriv_e[i,ii,j,l] = een_rescaled_e_deriv_e[i,ii,j,l] * een_rescaled_e[i,j,l]

#print(" een_rescaled_e_deriv_e[1, 1, 3, 1] = ",een_rescaled_e_deriv_e[0, 0, 2, 1])
#print(" een_rescaled_e_deriv_e[1, 1, 4, 1] = ",een_rescaled_e_deriv_e[0, 0, 3, 1])
#print(" een_rescaled_e_deriv_e[1, 1, 5, 1] = ",een_rescaled_e_deriv_e[0, 0, 4, 1])
#print(" een_rescaled_e_deriv_e[2, 1, 4, 2] = ",een_rescaled_e_deriv_e[1, 0, 3, 2])
#print(" een_rescaled_e_deriv_e[2, 1, 5, 2] = ",een_rescaled_e_deriv_e[1, 0, 4, 2])
#print(" een_rescaled_e_deriv_e[2, 1, 6, 2] = ",een_rescaled_e_deriv_e[1, 0, 5, 2])
    #+end_src

    #+RESULTS: een_e_deriv_e
    :  een_rescaled_e_deriv_e[1, 1, 3, 1] =  0.05991352796887283
    :  een_rescaled_e_deriv_e[1, 1, 4, 1] =  0.011714035071545248
    :  een_rescaled_e_deriv_e[1, 1, 5, 1] =  0.00441398875758468
    :  een_rescaled_e_deriv_e[2, 1, 4, 2] =  0.013553180060167595
    :  een_rescaled_e_deriv_e[2, 1, 5, 2] =  0.00041342909359870457
    :  een_rescaled_e_deriv_e[2, 1, 6, 2] =  0.5880599146214673

     #+begin_src c :tangle (eval c_test)
double een_rescaled_e_deriv_e[walk_num][(cord_num + 1)][elec_num][4][elec_num];
size_max=walk_num*(cord_num + 1)*elec_num*4*elec_num;
rc = qmckl_get_jastrow_een_rescaled_e_deriv_e(context,
          &(een_rescaled_e_deriv_e[0][0][0][0][0]),size_max);

// value of (0,0,0,2,1)
assert(fabs(een_rescaled_e_deriv_e[0][1][0][0][2] + 0.05991352796887283   ) < 1.e-12);
assert(fabs(een_rescaled_e_deriv_e[0][1][0][0][3] + 0.011714035071545248  ) < 1.e-12);
assert(fabs(een_rescaled_e_deriv_e[0][1][0][0][4] + 0.00441398875758468   ) < 1.e-12);
assert(fabs(een_rescaled_e_deriv_e[0][2][1][0][3] + 0.013553180060167595  ) < 1.e-12);
assert(fabs(een_rescaled_e_deriv_e[0][2][1][0][4] + 0.00041342909359870457) < 1.e-12);
assert(fabs(een_rescaled_e_deriv_e[0][2][1][0][5] + 0.5880599146214673    ) < 1.e-12);
     #+end_src

** Electron-nucleus rescaled distances

   ~en_distance_rescaled~ stores the matrix of the rescaled distances between
   electrons and nuclei.

   \[
   C_{ij} = \left( 1 - \exp{-\kappa C_{ij}}\right)/\kappa
   \]

  where \(C_{ij}\) is the matrix of electron-nucleus distances.

*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code qmckl_get_electron_en_distance_rescaled(qmckl_context context, double* distance_rescaled);
    #+end_src


    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_get_electron_en_distance_rescaled(qmckl_context context, double* distance_rescaled)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_en_distance_rescaled(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num;
  memcpy(distance_rescaled, ctx->jastrow.en_distance_rescaled, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_en_distance_rescaled(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_en_distance_rescaled(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!(ctx->nucleus.provided)) {
    return QMCKL_NOT_PROVIDED;
  }

  /* Compute if necessary */
  if (ctx->electron.walker.point.date > ctx->jastrow.en_distance_rescaled_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.en_distance_rescaled != NULL) {
        qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.en_distance_rescaled);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_en_distance_rescaled",
                                 "Unable to free ctx->jastrow.en_distance_rescaled");
        }
        ctx->jastrow.en_distance_rescaled = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.en_distance_rescaled == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.num * ctx->nucleus.num *
        ctx->electron.walker.num * sizeof(double);
      double* en_distance_rescaled = (double*) qmckl_malloc(context, mem_info);

      if (en_distance_rescaled == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_en_distance_rescaled",
                               NULL);
      }
      ctx->jastrow.en_distance_rescaled = en_distance_rescaled;
    }

    qmckl_exit_code rc =
      qmckl_compute_en_distance_rescaled(context,
                                ctx->electron.num,
                                ctx->nucleus.num,
                                ctx->jastrow.type_nucl_num,
                                ctx->jastrow.type_nucl_vector,
                                ctx->jastrow.rescale_factor_en,
                                ctx->electron.walker.num,
                                ctx->electron.walker.point.coord.data,
                                ctx->nucleus.coord.data,
                                ctx->jastrow.en_distance_rescaled);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.en_distance_rescaled_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_en_distance_rescaled
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

   #+NAME: qmckl_en_distance_rescaled_args
    | Variable               | Type                                   | In/Out | Description                       |
    |------------------------+----------------------------------------+--------+-----------------------------------|
    | ~context~              | ~qmckl_context~                        | in     | Global state                      |
    | ~elec_num~             | ~int64_t~                              | in     | Number of electrons               |
    | ~nucl_num~             | ~int64_t~                              | in     | Number of nuclei                  |
    | ~type_nucl_num~        | ~int64_t~                              | in     | Number of types of nuclei         |
    | ~type_nucl_vector~     | ~int64_t[nucl_num]~                    | in     | Number of types of nuclei         |
    | ~rescale_factor_en~    | ~double[type_nucl_num]~                | in     | The factor for rescaled distances |
    | ~walk_num~             | ~int64_t~                              | in     | Number of walkers                 |
    | ~elec_coord~           | ~double[3][walk_num][elec_num]~        | in     | Electron coordinates              |
    | ~nucl_coord~           | ~double[3][elec_num]~                  | in     | Nuclear coordinates               |
    | ~en_distance_rescaled~ | ~double[walk_num][nucl_num][elec_num]~ | out    | Electron-nucleus distances        |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_en_distance_rescaled_f(context, elec_num, nucl_num, type_nucl_num, &
     type_nucl_vector, rescale_factor_en, walk_num, elec_coord, &
     nucl_coord, en_distance_rescaled) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  double precision      , intent(in)  :: rescale_factor_en(type_nucl_num)
  integer*8             , intent(in)  :: walk_num
  double precision      , intent(in)  :: elec_coord(elec_num,walk_num,3)
  double precision      , intent(in)  :: nucl_coord(nucl_num,3)
  double precision      , intent(out) :: en_distance_rescaled(elec_num,nucl_num,walk_num)

  integer*8 :: i, k
  double precision      :: coord(3)

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  do i=1, nucl_num
     coord(1:3) = nucl_coord(i,1:3)
     do k=1,walk_num
        info = qmckl_distance_rescaled(context, 'T', 'T', elec_num, 1_8, &
             elec_coord(1,k,1), elec_num*walk_num, coord, 1_8, &
             en_distance_rescaled(1,i,k), elec_num, rescale_factor_en(type_nucl_vector(i)))
        if (info /= QMCKL_SUCCESS) then
           return
        endif
     end do
  end do

end function qmckl_compute_en_distance_rescaled_f
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org :exports none
qmckl_exit_code qmckl_compute_en_distance_rescaled (
          const qmckl_context context,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t type_nucl_num,
          int64_t* const type_nucl_vector,
          const double*  rescale_factor_en,
          const int64_t walk_num,
          const double* elec_coord,
          const double* nucl_coord,
          double* const en_distance_rescaled );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_en_distance_rescaled_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_en_distance_rescaled &
        (context, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         rescale_factor_en, &
         walk_num, &
         elec_coord, &
         nucl_coord, &
         en_distance_rescaled) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: type_nucl_num
      integer (c_int64_t) , intent(in)          :: type_nucl_vector(nucl_num)
      real    (c_double ) , intent(in)          :: rescale_factor_en(type_nucl_num)
      integer (c_int64_t) , intent(in)  , value :: walk_num
      real    (c_double ) , intent(in)          :: elec_coord(elec_num,walk_num,3)
      real    (c_double ) , intent(in)          :: nucl_coord(elec_num,3)
      real    (c_double ) , intent(out)         :: en_distance_rescaled(elec_num,nucl_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_en_distance_rescaled_f
      info = qmckl_compute_en_distance_rescaled_f &
             (context, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         rescale_factor_en, &
         walk_num, &
         elec_coord, &
         nucl_coord, &
         en_distance_rescaled)

    end function qmckl_compute_en_distance_rescaled
    #+end_src

*** Test

    #+begin_src python :results output :exports none
import numpy as np

kappa = 1.0

elec_1_w1 = np.array( [-0.250655104764153,  0.503070975550133      ,  -0.166554344502303])
elec_2_w1 = np.array( [-0.587812193472177, -0.128751981129274      ,   0.187773606533075])
elec_5_w1 = np.array( [-0.127732483187947, -0.138975497694196      ,  -8.669850480215846E-002])
elec_6_w1 = np.array( [-0.232271834949124, -1.059321673434182E-002 ,  -0.504862241464867])
nucl_1    = np.array( [ 0., 0., 0. ])
nucl_2    = np.array( [ 0., 0., 2.059801 ])

print ( "[0][0] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_1_w1-nucl_1)) )/kappa )
print ( "[1][0] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_1_w1-nucl_2)) )/kappa )
print ( "[0][1] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_2_w1-nucl_1)) )/kappa )
print ( "[0][5] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_5_w1-nucl_1)) )/kappa )
print ( "[1][5] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_5_w1-nucl_2)) )/kappa )
print ( "[0][6] : ", (1.0 - np.exp(-kappa * np.linalg.norm(elec_6_w1-nucl_1)) )/kappa )

    #+end_src

    #+RESULTS:
    : [0][0] :  0.4435709484118112
    : [1][0] :  0.8993601506374442
    : [0][1] :  0.46760219699910477
    : [0][5] :  0.1875631834682101
    : [1][5] :  0.8840716589810682
    : [0][6] :  0.42640469987268914

     #+begin_src c :tangle (eval c_test)

assert(qmckl_electron_provided(context));
assert(qmckl_nucleus_provided(context));

double en_distance_rescaled[walk_num][nucl_num][elec_num];

rc = qmckl_check(context,
                 qmckl_get_electron_en_distance_rescaled(context, &(en_distance_rescaled[0][0][0]))
                 );
assert (rc == QMCKL_SUCCESS);

// (e,n,w) in Fortran notation
// (1,1,1)
assert(fabs(en_distance_rescaled[0][0][0] - 0.4435709484118112) < 1.e-12);

// (1,2,1)
assert(fabs(en_distance_rescaled[0][1][0] - 0.8993601506374442) < 1.e-12);

// (2,1,1)
assert(fabs(en_distance_rescaled[0][0][1] - 0.46760219699910477) < 1.e-12);

// (1,1,2)
assert(fabs(en_distance_rescaled[0][0][5] - 0.1875631834682101) < 1.e-12);

// (1,2,2)
assert(fabs(en_distance_rescaled[0][1][5] - 0.8840716589810682) < 1.e-12);

// (2,1,2)
assert(fabs(en_distance_rescaled[0][0][6] - 0.42640469987268914) < 1.e-12);

     #+end_src

** Electron-electron-nucleus rescaled distance gradients and laplacian with respect to electron coords

  The rescaled distances which is given as $R = (1 - \exp{-\kappa r})/\kappa$
  needs to be perturbed with respect to the nuclear coordinates.
  This data is stored in the ~en_distance_rescaled_deriv_e~ tensor. The
  The first three elements of this three index tensor ~[4][nucl_num][elec_num]~ gives the
  derivatives in the x, y, and z directions $dx, dy, dz$ and the last index
  gives the Laplacian $\partial x^2 + \partial y^2 + \partial z^2$.

*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code qmckl_get_electron_en_distance_rescaled_deriv_e(qmckl_context context, double* distance_rescaled_deriv_e);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_get_electron_en_distance_rescaled_deriv_e(qmckl_context context, double* distance_rescaled_deriv_e)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_en_distance_rescaled_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = 4 * ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num;
  memcpy(distance_rescaled_deriv_e, ctx->jastrow.en_distance_rescaled_deriv_e, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_en_distance_rescaled_deriv_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_en_distance_rescaled_deriv_e(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  if (!(ctx->nucleus.provided)) {
    return QMCKL_NOT_PROVIDED;
  }

  /* Compute if necessary */
  if (ctx->electron.walker.point.date > ctx->jastrow.en_distance_rescaled_deriv_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.en_distance_rescaled_deriv_e != NULL) {
        qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.en_distance_rescaled_deriv_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_en_distance_rescaled_deriv_e",
                                 "Unable to free ctx->jastrow.en_distance_rescaled_deriv_e");
        }
        ctx->jastrow.en_distance_rescaled_deriv_e = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.en_distance_rescaled_deriv_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = 4 * ctx->electron.num * ctx->nucleus.num *
        ctx->electron.walker.num * sizeof(double);
      double* en_distance_rescaled_deriv_e = (double*) qmckl_malloc(context, mem_info);

      if (en_distance_rescaled_deriv_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_en_distance_rescaled_deriv_e",
                               NULL);
      }
      ctx->jastrow.en_distance_rescaled_deriv_e = en_distance_rescaled_deriv_e;
    }

    qmckl_exit_code rc =
      qmckl_compute_en_distance_rescaled_deriv_e(context,
                                ctx->electron.num,
                                ctx->nucleus.num,
                                ctx->jastrow.type_nucl_num,
                                ctx->jastrow.type_nucl_vector,
                                ctx->jastrow.rescale_factor_en,
                                ctx->electron.walker.num,
                                ctx->electron.walker.point.coord.data,
                                ctx->nucleus.coord.data,
                                ctx->jastrow.en_distance_rescaled_deriv_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.en_distance_rescaled_deriv_e_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_en_distance_rescaled_deriv_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_en_distance_rescaled_deriv_e_args
    | Variable                       | Type                                      | In/Out | Description                           |
    |--------------------------------+-------------------------------------------+--------+---------------------------------------|
    | ~context~                      | ~qmckl_context~                           | in     | Global state                          |
    | ~elec_num~                     | ~int64_t~                                 | in     | Number of electrons                   |
    | ~nucl_num~                     | ~int64_t~                                 | in     | Number of nuclei                      |
    | ~type_nucl_num~                | ~int64_t~                                 | in     | Number of nucleus types               |
    | ~type_nucl_vector~             | ~int64_t[nucl_num]~                       | in     | Array of nucleus types                |
    | ~rescale_factor_en~            | ~double[nucl_num]~                        | in     | The factors for rescaled distances    |
    | ~walk_num~                     | ~int64_t~                                 | in     | Number of walkers                     |
    | ~elec_coord~                   | ~double[3][walk_num][elec_num]~           | in     | Electron coordinates                  |
    | ~nucl_coord~                   | ~double[3][elec_num]~                     | in     | Nuclear coordinates                   |
    | ~en_distance_rescaled_deriv_e~ | ~double[walk_num][nucl_num][elec_num][4]~ | out    | Electron-nucleus distance derivatives |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_en_distance_rescaled_deriv_e_f(context, elec_num, nucl_num, &
     type_nucl_num, type_nucl_vector, rescale_factor_en, walk_num, elec_coord, &
     nucl_coord, en_distance_rescaled_deriv_e) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  double precision      , intent(in)  :: rescale_factor_en(nucl_num)
  integer*8             , intent(in)  :: walk_num
  double precision      , intent(in)  :: elec_coord(elec_num,walk_num,3)
  double precision      , intent(in)  :: nucl_coord(nucl_num,3)
  double precision      , intent(out) :: en_distance_rescaled_deriv_e(4,elec_num,nucl_num,walk_num)

  integer*8 :: i, k
  double precision :: coord(3)

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  do i=1, nucl_num
     coord(1:3) = nucl_coord(i,1:3)
     do k=1,walk_num
        info = qmckl_distance_rescaled_deriv_e(context, 'T', 'T', elec_num, 1_8, &
             elec_coord(1,k,1), elec_num*walk_num, coord, 1_8, &
             en_distance_rescaled_deriv_e(1,1,i,k), elec_num, rescale_factor_en(type_nucl_vector(i)))
        if (info /= QMCKL_SUCCESS) then
           return
        endif
     end do
  end do

end function qmckl_compute_en_distance_rescaled_deriv_e_f
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org :exports none
qmckl_exit_code qmckl_compute_en_distance_rescaled_deriv_e (
          const qmckl_context context,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t type_nucl_num,
          int64_t* const type_nucl_vector,
          const double*  rescale_factor_en,
          const int64_t walk_num,
          const double* elec_coord,
          const double* nucl_coord,
          double* const en_distance_rescaled_deriv_e );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_en_distance_rescaled_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_en_distance_rescaled_deriv_e &
        (context, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         rescale_factor_en, &
         walk_num, &
         elec_coord, &
         nucl_coord, &
         en_distance_rescaled_deriv_e) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: type_nucl_num
      integer (c_int64_t) , intent(in)          :: type_nucl_vector(nucl_num)
      real    (c_double ) , intent(in)          :: rescale_factor_en(nucl_num)
      integer (c_int64_t) , intent(in)  , value :: walk_num
      real    (c_double ) , intent(in)          :: elec_coord(elec_num,walk_num,3)
      real    (c_double ) , intent(in)          :: nucl_coord(elec_num,3)
      real    (c_double ) , intent(out)         :: en_distance_rescaled_deriv_e(4,elec_num,nucl_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_en_distance_rescaled_deriv_e_f
      info = qmckl_compute_en_distance_rescaled_deriv_e_f &
             (context, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         rescale_factor_en, &
         walk_num, &
         elec_coord, &
         nucl_coord, &
         en_distance_rescaled_deriv_e)

    end function qmckl_compute_en_distance_rescaled_deriv_e
    #+end_src

*** Test

    #+begin_src python :results output :exports none
import numpy as np

# TODO
    #+end_src


     #+begin_src c :tangle (eval c_test)

assert(qmckl_electron_provided(context));

assert(qmckl_nucleus_provided(context));

double en_distance_rescaled_deriv_e[walk_num][4][nucl_num][elec_num];

rc = qmckl_check(context,
                 qmckl_get_electron_en_distance_rescaled_deriv_e(context, &(en_distance_rescaled_deriv_e[0][0][0][0]))
                 );
assert (rc == QMCKL_SUCCESS);

// TODO: check exact values
//// (e,n,w) in Fortran notation
//// (1,1,1)
//assert(fabs(en_distance_rescaled[0][0][0] - 7.546738741619978) < 1.e-12);
//
//// (1,2,1)
//assert(fabs(en_distance_rescaled[0][1][0] - 8.77102435246984) < 1.e-12);
//
//// (2,1,1)
//assert(fabs(en_distance_rescaled[0][0][1] - 3.698922010513608) < 1.e-12);
//
//// (1,1,2)
//assert(fabs(en_distance_rescaled[1][0][0] - 5.824059436060509) < 1.e-12);
//
//// (1,2,2)
//assert(fabs(en_distance_rescaled[1][1][0] - 7.080482110317645) < 1.e-12);
//
//// (2,1,2)
//assert(fabs(en_distance_rescaled[1][0][1] - 3.1804527583077356) < 1.e-12);

     #+end_src

** Electron-electron-nucleus rescaled distances for each order

   ~een_rescaled_n~ stores the table of the rescaled distances between
   electrons and nucleii raised to the power \(p\) defined by ~cord_num~:

   \[
   C_{ia,p} = \left( 1 - \exp{-\kappa C_{ia}} \right)^p
   \]

  where \(C_{ia}\) is the matrix of electron-nucleus distances.

*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_n(qmckl_context context,
                                 double* const distance_rescaled,
                                 const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_n(qmckl_context context,
                                 double* const distance_rescaled,
                                 const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_een_rescaled_n(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1);
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_een_deriv_e",
                           "Array too small. Expected ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1)");
  }
  memcpy(distance_rescaled, ctx->jastrow.een_rescaled_n, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_een_rescaled_n(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_een_rescaled_n(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Check if ee distance is provided */
  qmckl_exit_code rc = qmckl_provide_en_distance(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.een_rescaled_n_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.een_rescaled_n != NULL) {
        rc = qmckl_free(context, ctx->jastrow.een_rescaled_n);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_een_rescaled_n",
                                 "Unable to free ctx->jastrow.een_rescaled_n");
        }
        ctx->jastrow.een_rescaled_n = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.een_rescaled_n == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.num * ctx->nucleus.num *
        ctx->electron.walker.num * (ctx->jastrow.cord_num + 1) * sizeof(double);
      double* een_rescaled_n = (double*) qmckl_malloc(context, mem_info);

      if (een_rescaled_n == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_een_rescaled_n",
                               NULL);
      }
      ctx->jastrow.een_rescaled_n = een_rescaled_n;
    }

    rc = qmckl_compute_een_rescaled_n(context,
                                      ctx->electron.walker.num,
                                      ctx->electron.num,
                                      ctx->nucleus.num,
                                      ctx->jastrow.type_nucl_num,
                                      ctx->jastrow.type_nucl_vector,
                                      ctx->jastrow.cord_num,
                                      ctx->jastrow.rescale_factor_en,
                                      ctx->electron.en_distance,
                                      ctx->jastrow.een_rescaled_n);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.een_rescaled_n_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_een_rescaled_n
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_een_rescaled_n_args
    | Variable            | Type                                               | In/Out | Description                         |
    |---------------------+----------------------------------------------------+--------+-------------------------------------|
    | ~context~           | ~qmckl_context~                                    | in     | Global state                        |
    | ~walk_num~          | ~int64_t~                                          | in     | Number of walkers                   |
    | ~elec_num~          | ~int64_t~                                          | in     | Number of electrons                 |
    | ~nucl_num~          | ~int64_t~                                          | in     | Number of atoms                     |
    | ~type_nucl_num~     | ~int64_t~                                          | in     | Number of atom types                |
    | ~type_nucl_vector~  | ~int64_t[nucl_num]~                                | in     | Types of atoms                      |
    | ~cord_num~          | ~int64_t~                                          | in     | Order of polynomials                |
    | ~rescale_factor_en~ | ~double[nucl_num]~                                 | in     | Factor to rescale ee distances      |
    | ~en_distance~       | ~double[walk_num][elec_num][nucl_num]~             | in     | Electron-nucleus distances          |
    | ~een_rescaled_n~    | ~double[walk_num][0:cord_num][nucl_num][elec_num]~ | out    | Electron-nucleus rescaled distances |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_een_rescaled_n_f( &
     context, walk_num, elec_num, nucl_num, &
     type_nucl_num, type_nucl_vector, cord_num, rescale_factor_en,  &
     en_distance, een_rescaled_n) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  integer*8             , intent(in)  :: cord_num
  double precision      , intent(in)  :: rescale_factor_en(type_nucl_num)
  double precision      , intent(in)  :: en_distance(elec_num,nucl_num,walk_num)
  double precision      , intent(out) :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)
  double precision                    :: x
  integer*8                           :: i, a, k, l, nw

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  ! Prepare table of exponentiated distances raised to appropriate power
  een_rescaled_n             = 0.0d0
  do nw = 1, walk_num
     
     ! prepare the actual een table
     een_rescaled_n(:, :, 0, nw) = 1.0d0
     
     do a = 1, nucl_num
        do i = 1, elec_num
           een_rescaled_n(i, a, 1, nw) = dexp(-rescale_factor_en(type_nucl_vector(a)) * en_distance(i, a, nw))
        end do
     end do
     
     do l = 2, cord_num
        do a = 1, nucl_num
           do i = 1, elec_num
              een_rescaled_n(i, a, l, nw) = een_rescaled_n(i, a, l - 1, nw) * een_rescaled_n(i, a, 1, nw)
           end do
        end do
     end do

  end do

end function qmckl_compute_een_rescaled_n_f
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
/*
qmckl_exit_code qmckl_compute_een_rescaled_n (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t type_nucl_num,
      int64_t* const type_nucl_vector,
      const int64_t cord_num,
      const double* rescale_factor_en,
      const double* en_distance,
      double* const een_rescaled_n ) {


  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (walk_num <= 0) {
    return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
    return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
    return QMCKL_INVALID_ARG_4;
  }

  if (cord_num < 0) {
    return QMCKL_INVALID_ARG_5;
  }

  // Prepare table of exponentiated distances raised to appropriate power
  for (int i = 0; i < (walk_num*(cord_num+1)*nucl_num*elec_num); ++i) {
    een_rescaled_n[i] = 1.0;
  }

  for (int nw = 0; nw < walk_num; ++nw) {
    for (int a = 0; a < nucl_num; ++a) {
      for (int i = 0; i < elec_num; ++i) {
        een_rescaled_n[i + a*elec_num + nw * elec_num*nucl_num*(cord_num+1)] = 1.0;
        een_rescaled_n[i + a*elec_num + elec_num*nucl_num + nw*elec_num*nucl_num*(cord_num+1)] =
          exp(-rescale_factor_en[type_nucl_vector[a]] * en_distance[i + a*elec_num + nw*elec_num*nucl_num]);
      }
    }

    for (int l = 2; l < (cord_num+1); ++l){
      for (int a = 0; a < nucl_num; ++a) {
        for (int i = 0; i < elec_num; ++i) {
          een_rescaled_n[i + a*elec_num + l*elec_num*nucl_num + nw*elec_num*nucl_num*(cord_num+1)] =
            een_rescaled_n[i + a*elec_num + (l-1)*elec_num*nucl_num + nw*elec_num*nucl_num*(cord_num+1)] * 
            een_rescaled_n[i + a*elec_num +       elec_num*nucl_num + nw*elec_num*nucl_num*(cord_num+1)];
        }
      }
    }

  }

  return QMCKL_SUCCESS;
}
*/
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_factor_een_rescaled_n_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_een_rescaled_n &
        (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         cord_num, &
         rescale_factor_en, &
         en_distance, &
         een_rescaled_n) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: type_nucl_num
      integer (c_int64_t) , intent(in)          :: type_nucl_vector(nucl_num)
      integer (c_int64_t) , intent(in)  , value :: cord_num
      real    (c_double ) , intent(in)          :: rescale_factor_en(nucl_num)
      real    (c_double ) , intent(in)          :: en_distance(nucl_num,elec_num,walk_num)
      real    (c_double ) , intent(out)         :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_een_rescaled_n_f
      info = qmckl_compute_een_rescaled_n_f &
             (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         cord_num, &
         rescale_factor_en, &
         en_distance, &
         een_rescaled_n)

    end function qmckl_compute_een_rescaled_n
    #+end_src
    
#   #+CALL: generate_c_header(table=qmckl_factor_een_rescaled_n_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_een_rescaled_n (
          const qmckl_context context,
          const int64_t walk_num,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t type_nucl_num,
          int64_t* const type_nucl_vector,
          const int64_t cord_num,
          const double* rescale_factor_en,
          const double* en_distance,
          double* const een_rescaled_n );
    #+end_src

*** Test

    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

elec_coord = np.array(elec_coord)[0]
nucl_coord = np.array(nucl_coord)
elnuc_dist = np.zeros(shape=(elec_num, nucl_num),dtype=float)
for i in range(elec_num):
  for a in range(nucl_num):
    elnuc_dist[i, a] = np.linalg.norm(elec_coord[i] - nucl_coord[:,a])

kappa = 1.0

een_rescaled_n = np.zeros(shape=(nucl_num, elec_num, cord_num + 1), dtype=float)
een_rescaled_n[:,:,0] = 1.0

for a in range(nucl_num):
  for i in range(elec_num):
    een_rescaled_n[a, i, 1] = np.exp(-kappa * elnuc_dist[i, a])

for l in range(2,cord_num+1):
  for a in range(nucl_num):
    for i in range(elec_num):
      een_rescaled_n[a, i, l] = een_rescaled_n[a, i, l - 1] * een_rescaled_n[a, i, 1]

print(" een_rescaled_n[0, 2, 1] = ",een_rescaled_n[0, 2, 1])
print(" een_rescaled_n[0, 3, 1] = ",een_rescaled_n[0, 3, 1])
print(" een_rescaled_n[0, 4, 1] = ",een_rescaled_n[0, 4, 1])
print(" een_rescaled_n[1, 3, 2] = ",een_rescaled_n[1, 3, 2])
print(" een_rescaled_n[1, 4, 2] = ",een_rescaled_n[1, 4, 2])
print(" een_rescaled_n[1, 5, 2] = ",een_rescaled_n[1, 5, 2])
    #+end_src

    #+RESULTS:
    :  een_rescaled_n[0, 2, 1] =  0.10612983920006765
    :  een_rescaled_n[0, 3, 1] =  0.135652809635553
    :  een_rescaled_n[0, 4, 1] =  0.023391817607642338
    :  een_rescaled_n[1, 3, 2] =  0.880957224822116
    :  een_rescaled_n[1, 4, 2] =  0.027185942659395074
    :  een_rescaled_n[1, 5, 2] =  0.01343938025140174

     #+begin_src c :tangle (eval c_test)
assert(qmckl_electron_provided(context));

double een_rescaled_n[walk_num][(cord_num + 1)][nucl_num][elec_num];
size_max=walk_num*(cord_num + 1)*nucl_num*elec_num;
rc = qmckl_get_jastrow_een_rescaled_n(context, &(een_rescaled_n[0][0][0][0]),size_max);

// value of (0,2,1)
assert(fabs(een_rescaled_n[0][1][0][2]-0.10612983920006765)  < 1.e-12);
assert(fabs(een_rescaled_n[0][1][0][3]-0.135652809635553)    < 1.e-12);
assert(fabs(een_rescaled_n[0][1][0][4]-0.023391817607642338) < 1.e-12);
assert(fabs(een_rescaled_n[0][2][1][3]-0.880957224822116)    < 1.e-12);
assert(fabs(een_rescaled_n[0][2][1][4]-0.027185942659395074) < 1.e-12);
assert(fabs(een_rescaled_n[0][2][1][5]-0.01343938025140174)  < 1.e-12);
     #+end_src

** Electron-nucleus rescaled distances for each order and derivatives

   ~een_rescaled_n_deriv_e~ stores the table of the rescaled distances between
   electrons and nucleii raised to the power \(p\) defined by ~cord_num~:


*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_n_deriv_e(qmckl_context context,
                                         double* const distance_rescaled,
                                         const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_een_rescaled_n_deriv_e(qmckl_context context,
                                         double* const distance_rescaled,
                                         const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_een_rescaled_n_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * 4 * ctx->nucleus.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1);
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_een_deriv_e",
                           "Array too small. Expected ctx->electron.num * 4 * ctx->nucleus.num * ctx->electron.walker.num * (ctx->jastrow.cord_num + 1)");
  }
  memcpy(distance_rescaled, ctx->jastrow.een_rescaled_n_deriv_e, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_een_rescaled_n_deriv_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_een_rescaled_n_deriv_e(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Check if ee distance is provided */
  qmckl_exit_code rc = qmckl_provide_en_distance(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if ee distance is provided */
  rc = qmckl_provide_een_rescaled_n(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.een_rescaled_n_deriv_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.een_rescaled_n_deriv_e != NULL) {
        rc = qmckl_free(context, ctx->jastrow.een_rescaled_n_deriv_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_een_rescaled_n_deriv_e",
                                 "Unable to free ctx->jastrow.een_rescaled_n_deriv_e");
        }
        ctx->jastrow.een_rescaled_n_deriv_e = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.een_rescaled_n_deriv_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.num * 4 * ctx->nucleus.num *
        ctx->electron.walker.num * (ctx->jastrow.cord_num + 1) * sizeof(double);
      double* een_rescaled_n_deriv_e = (double*) qmckl_malloc(context, mem_info);

      if (een_rescaled_n_deriv_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_een_rescaled_n_deriv_e",
                               NULL);
      }
      ctx->jastrow.een_rescaled_n_deriv_e = een_rescaled_n_deriv_e;
    }

    rc = qmckl_compute_factor_een_rescaled_n_deriv_e(context,
                                                     ctx->electron.walker.num,
                                                     ctx->electron.num,
                                                     ctx->nucleus.num,
                                                     ctx->jastrow.type_nucl_num,
                                                     ctx->jastrow.type_nucl_vector,
                                                     ctx->jastrow.cord_num,
                                                     ctx->jastrow.rescale_factor_en,
                                                     ctx->electron.walker.point.coord.data,
                                                     ctx->nucleus.coord.data,
                                                     ctx->electron.en_distance,
                                                     ctx->jastrow.een_rescaled_n,
                                                     ctx->jastrow.een_rescaled_n_deriv_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.een_rescaled_n_deriv_e_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_een_rescaled_n_deriv_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_compute_factor_een_rescaled_n_deriv_e_args
    | Variable                 | Type                                                  | In/Out | Description                         |
    |--------------------------+-------------------------------------------------------+--------+-------------------------------------|
    | ~context~                | ~qmckl_context~                                       | in     | Global state                        |
    | ~walk_num~               | ~int64_t~                                             | in     | Number of walkers                   |
    | ~elec_num~               | ~int64_t~                                             | in     | Number of electrons                 |
    | ~nucl_num~               | ~int64_t~                                             | in     | Number of atoms                     |
    | ~type_nucl_num~          | ~int64_t~                                             | in     | Number of atom types                |
    | ~type_nucl_vector~       | ~int64_t[nucl_num]~                                   | in     | Types of atoms                      |
    | ~cord_num~               | ~int64_t~                                             | in     | Order of polynomials                |
    | ~rescale_factor_en~      | ~double[nucl_num]~                                    | in     | Factor to rescale ee distances      |
    | ~coord_ee~               | ~double[walk_num][3][elec_num]~                       | in     | Electron coordinates                |
    | ~coord_en~               | ~double[3][nucl_num]~                                 | in     | Nuclear coordinates                 |
    | ~en_distance~            | ~double[walk_num][elec_num][nucl_num]~                | in     | Electron-nucleus distances          |
    | ~een_rescaled_n~         | ~double[walk_num][0:cord_num][nucl_num][elec_num]~    | in     | Electron-nucleus distances          |
    | ~een_rescaled_n_deriv_e~ | ~double[walk_num][0:cord_num][nucl_num][4][elec_num]~ | out    | Electron-nucleus rescaled distances |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_een_rescaled_n_deriv_e_f( &
     context, walk_num, elec_num, nucl_num, type_nucl_num, type_nucl_vector, &
     cord_num, rescale_factor_en, &
     coord_ee, coord_en, en_distance, een_rescaled_n, een_rescaled_n_deriv_e) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  integer*8             , intent(in)  :: cord_num
  double precision      , intent(in)  :: rescale_factor_en(type_nucl_num)
  double precision      , intent(in)  :: coord_ee(elec_num,3,walk_num)
  double precision      , intent(in)  :: coord_en(nucl_num,3)
  double precision      , intent(in)  :: en_distance(elec_num,nucl_num,walk_num)
  double precision      , intent(in)  :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)
  double precision      , intent(out) :: een_rescaled_n_deriv_e(elec_num,4,nucl_num,0:cord_num,walk_num)
  double precision,dimension(:,:,:),allocatable :: elnuc_dist_deriv_e
  double precision                    :: x, ria_inv, kappa_l
  integer*8                           :: i, a, k, l, nw, ii

  allocate(elnuc_dist_deriv_e(4, elec_num, nucl_num))

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  ! Prepare table of exponentiated distances raised to appropriate power
  een_rescaled_n_deriv_e             = 0.0d0
  do nw = 1, walk_num

  ! prepare the actual een table
  do a = 1, nucl_num
    do i = 1, elec_num
      ria_inv = 1.0d0 / en_distance(i, a, nw)
      do ii = 1, 3
        elnuc_dist_deriv_e(ii, i, a) = (coord_ee(i, ii, nw) - coord_en(a, ii)) * ria_inv
      end do
      elnuc_dist_deriv_e(4, i, a) = 2.0d0 * ria_inv
    end do
  end do

  do l = 0, cord_num
    do a = 1, nucl_num
      kappa_l = - dble(l) * rescale_factor_en(type_nucl_vector(a))
      do i = 1, elec_num
        een_rescaled_n_deriv_e(i, 1, a, l, nw) = kappa_l * elnuc_dist_deriv_e(1, i, a)
        een_rescaled_n_deriv_e(i, 2, a, l, nw) = kappa_l * elnuc_dist_deriv_e(2, i, a)
        een_rescaled_n_deriv_e(i, 3, a, l, nw) = kappa_l * elnuc_dist_deriv_e(3, i, a)
        een_rescaled_n_deriv_e(i, 4, a, l, nw) = kappa_l * elnuc_dist_deriv_e(4, i, a)

        een_rescaled_n_deriv_e(i, 4, a, l, nw) = een_rescaled_n_deriv_e(i, 4, a, l, nw)           &
                + een_rescaled_n_deriv_e(i, 1, a, l, nw) * een_rescaled_n_deriv_e(i, 1, a, l, nw) &
                + een_rescaled_n_deriv_e(i, 2, a, l, nw) * een_rescaled_n_deriv_e(i, 2, a, l, nw) &
                + een_rescaled_n_deriv_e(i, 3, a, l, nw) * een_rescaled_n_deriv_e(i, 3, a, l, nw)

        een_rescaled_n_deriv_e(i, 1, a, l, nw) = een_rescaled_n_deriv_e(i, 1, a, l, nw) * &
                                                  een_rescaled_n(i, a, l, nw)
        een_rescaled_n_deriv_e(i, 2, a, l, nw) = een_rescaled_n_deriv_e(i, 2, a, l, nw) * &
                                                  een_rescaled_n(i, a, l, nw)
        een_rescaled_n_deriv_e(i, 3, a, l, nw) = een_rescaled_n_deriv_e(i, 3, a, l, nw) * &
                                                  een_rescaled_n(i, a, l, nw)
        een_rescaled_n_deriv_e(i, 4, a, l, nw) = een_rescaled_n_deriv_e(i, 4, a, l, nw) * &
                                                  een_rescaled_n(i, a, l, nw)
      end do
    end do
  end do
  end do

end function qmckl_compute_factor_een_rescaled_n_deriv_e_f
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_compute_factor_een_rescaled_n_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_een_rescaled_n_deriv_e (
          const qmckl_context context,
          const int64_t walk_num,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t type_nucl_num,
          int64_t* const type_nucl_vector,
          const int64_t cord_num,
          const double* rescale_factor_en,
          const double* coord_ee,
          const double* coord_en,
          const double* en_distance,
          const double* een_rescaled_n,
          double* const een_rescaled_n_deriv_e );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_compute_factor_een_rescaled_n_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_factor_een_rescaled_n_deriv_e &
        (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         cord_num, &
         rescale_factor_en, &
         coord_ee, &
         coord_en, &
         en_distance, &
         een_rescaled_n, &
         een_rescaled_n_deriv_e) &
        bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: type_nucl_num
      integer (c_int64_t) , intent(in)          :: type_nucl_vector(nucl_num)
      integer (c_int64_t) , intent(in)  , value :: cord_num
      real    (c_double ) , intent(in)          :: rescale_factor_en(nucl_num)
      real    (c_double ) , intent(in)          :: coord_ee(elec_num,3,walk_num)
      real    (c_double ) , intent(in)          :: coord_en(nucl_num,3)
      real    (c_double ) , intent(in)          :: en_distance(nucl_num,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)
      real    (c_double ) , intent(out)         :: een_rescaled_n_deriv_e(elec_num,4,nucl_num,0:cord_num,walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_een_rescaled_n_deriv_e_f
      info = qmckl_compute_factor_een_rescaled_n_deriv_e_f &
             (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         type_nucl_num, &
         type_nucl_vector, &
         cord_num, &
         rescale_factor_en, &
         coord_ee, &
         coord_en, &
         en_distance, &
         een_rescaled_n, &
         een_rescaled_n_deriv_e)

    end function qmckl_compute_factor_een_rescaled_n_deriv_e
    #+end_src

*** Test

    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

elec_coord = np.array(elec_coord)[0]
nucl_coord = np.array(nucl_coord)
elnuc_dist = np.zeros(shape=(elec_num, nucl_num),dtype=float)
for i in range(elec_num):
  for a in range(nucl_num):
    elnuc_dist[i, a] = np.linalg.norm(elec_coord[i] - nucl_coord[:,a])

elnuc_dist_deriv_e = np.zeros(shape=(4, elec_num, nucl_num),dtype=float)
for a in range(nucl_num):
  for i in range(elec_num):
    rij_inv = 1.0 / elnuc_dist[i, a]
    for ii in range(3):
      elnuc_dist_deriv_e[ii, i, a] = (elec_coord[i][ii] - nucl_coord[ii][a]) * rij_inv
    elnuc_dist_deriv_e[3, i, a] = 2.0 * rij_inv

kappa = 1.0

een_rescaled_n = np.zeros(shape=(nucl_num, elec_num, cord_num + 1), dtype=float)
een_rescaled_n[:,:,0] = 1.0

for a in range(nucl_num):
  for i in range(elec_num):
    een_rescaled_n[a, i, 1] = np.exp(-kappa * elnuc_dist[i, a])

for l in range(2,cord_num+1):
  for a in range(nucl_num):
    for i in range(elec_num):
      een_rescaled_n[a, i, l] = een_rescaled_n[a, i, l - 1] * een_rescaled_n[a, i, 1]

een_rescaled_n_deriv_e = np.zeros(shape=(elec_num,4,nucl_num,cord_num+1),dtype=float)
for l in range(0,cord_num+1):
  kappa_l = -1.0 * kappa * l
  for j in range(0,elec_num):
    for a in range(0,nucl_num):
      for ii in range(0,4):
        een_rescaled_n_deriv_e[j,ii,a,l] = kappa_l * elnuc_dist_deriv_e[ii,j,a]
      een_rescaled_n_deriv_e[j,3,a,l] = een_rescaled_n_deriv_e[j,3,a,l] +        \
      een_rescaled_n_deriv_e[j,0,a,l] * een_rescaled_n_deriv_e[j,0,a,l] +        \
      een_rescaled_n_deriv_e[j,1,a,l] * een_rescaled_n_deriv_e[j,1,a,l] +        \
      een_rescaled_n_deriv_e[j,2,a,l] * een_rescaled_n_deriv_e[j,2,a,l]

      for ii in range(0,4):
        een_rescaled_n_deriv_e[j,ii,a,l] = een_rescaled_n_deriv_e[j,ii,a,l] * een_rescaled_n[a,j,l]

print(" een_rescaled_n_deriv_e[1, 1, 3, 1] = ",een_rescaled_n_deriv_e[2, 0, 0, 1])
print(" een_rescaled_n_deriv_e[1, 1, 4, 1] = ",een_rescaled_n_deriv_e[3, 0, 0, 1])
print(" een_rescaled_n_deriv_e[1, 1, 5, 1] = ",een_rescaled_n_deriv_e[4, 0, 0, 1])
print(" een_rescaled_n_deriv_e[2, 1, 4, 2] = ",een_rescaled_n_deriv_e[3, 0, 1, 2])
print(" een_rescaled_n_deriv_e[2, 1, 5, 2] = ",een_rescaled_n_deriv_e[4, 0, 1, 2])
print(" een_rescaled_n_deriv_e[2, 1, 6, 2] = ",een_rescaled_n_deriv_e[5, 0, 1, 2])
    #+end_src

    #+RESULTS:
    :  een_rescaled_n_deriv_e[1, 1, 3, 1] =  -0.07633444246999128
    :  een_rescaled_n_deriv_e[1, 1, 4, 1] =  0.00033282346259738276
    :  een_rescaled_n_deriv_e[1, 1, 5, 1] =  -0.004775370547333061
    :  een_rescaled_n_deriv_e[2, 1, 4, 2] =  0.1362654644223866
    :  een_rescaled_n_deriv_e[2, 1, 5, 2] =  -0.0231253431662794
    :  een_rescaled_n_deriv_e[2, 1, 6, 2] =  0.001593334817691633

     #+begin_src c :tangle (eval c_test)
assert(qmckl_electron_provided(context));

double een_rescaled_n_deriv_e[walk_num][(cord_num + 1)][nucl_num][4][elec_num];
size_max=walk_num*(cord_num + 1)*nucl_num*4*elec_num;
rc = qmckl_get_jastrow_een_rescaled_n_deriv_e(context, &(een_rescaled_n_deriv_e[0][0][0][0][0]),size_max);

// value of (0,2,1)
assert(fabs(een_rescaled_n_deriv_e[0][1][0][0][2]+0.07633444246999128   )  < 1.e-12);
assert(fabs(een_rescaled_n_deriv_e[0][1][0][0][3]-0.00033282346259738276)  < 1.e-12);
assert(fabs(een_rescaled_n_deriv_e[0][1][0][0][4]+0.004775370547333061  )  < 1.e-12);
assert(fabs(een_rescaled_n_deriv_e[0][2][1][0][3]-0.1362654644223866    )  < 1.e-12);
assert(fabs(een_rescaled_n_deriv_e[0][2][1][0][4]+0.0231253431662794    )  < 1.e-12);
assert(fabs(een_rescaled_n_deriv_e[0][2][1][0][5]-0.001593334817691633  )  < 1.e-12);

     #+end_src

** Prepare for electron-electron-nucleus Jastrow \(f_{een}\)

  Prepare ~c_vector_full~ and ~lkpm_combined_index~ tables required for the
  calculation of the three-body jastrow ~factor_een~ and its derivative
  ~factor_een_deriv_e~.

*** Get

    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code qmckl_get_jastrow_dim_c_vector(qmckl_context context, int64_t* const dim_c_vector);
qmckl_exit_code qmckl_get_jastrow_c_vector_full(qmckl_context context, double* const c_vector_full);
qmckl_exit_code qmckl_get_jastrow_lkpm_combined_index(qmckl_context context, int64_t* const lkpm_combined_index);
qmckl_exit_code qmckl_get_jastrow_tmp_c(qmckl_context context, double* const tmp_c);
qmckl_exit_code qmckl_get_jastrow_dtmp_c(qmckl_context context, double* const dtmp_c);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_get_jastrow_dim_c_vector(qmckl_context context, int64_t* const dim_c_vector)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  *dim_c_vector = ctx->jastrow.dim_c_vector;

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_c_vector_full(qmckl_context context, double* const c_vector_full)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_c_vector_full(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = ctx->jastrow.dim_c_vector * ctx->nucleus.num;
  memcpy(c_vector_full, ctx->jastrow.c_vector_full, sze * sizeof(double));

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_lkpm_combined_index(qmckl_context context, int64_t* const lkpm_combined_index)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_c_vector_full(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = ctx->jastrow.dim_c_vector * 4;
  memcpy(lkpm_combined_index, ctx->jastrow.lkpm_combined_index, sze * sizeof(double));

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_tmp_c(qmckl_context context, double* const tmp_c)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_c_vector_full(context);
  if (rc != QMCKL_SUCCESS) return rc;

  rc = qmckl_provide_tmp_c(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = (ctx->jastrow.cord_num) * (ctx->jastrow.cord_num + 1)
               * ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num;
  memcpy(tmp_c, ctx->jastrow.tmp_c, sze * sizeof(double));

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_dtmp_c(qmckl_context context, double* const dtmp_c)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_jastrow_c_vector_full(context);
  if (rc != QMCKL_SUCCESS) return rc;

  rc = qmckl_provide_dtmp_c(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  size_t sze = (ctx->jastrow.cord_num) * (ctx->jastrow.cord_num + 1)
               *4* ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num;
  memcpy(dtmp_c, ctx->jastrow.dtmp_c, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_jastrow_c_vector_full(qmckl_context context);
qmckl_exit_code qmckl_provide_lkpm_combined_index(qmckl_context context);
qmckl_exit_code qmckl_provide_tmp_c(qmckl_context context);
qmckl_exit_code qmckl_provide_dtmp_c(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_jastrow_c_vector_full(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.c_vector_full_date) {

    /* Allocate array */
    if (ctx->jastrow.c_vector_full == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->jastrow.dim_c_vector * ctx->nucleus.num * sizeof(double);
      double* c_vector_full = (double*) qmckl_malloc(context, mem_info);

      if (c_vector_full == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_jastrow_c_vector_full",
                               NULL);
      }
      ctx->jastrow.c_vector_full = c_vector_full;
    }

    qmckl_exit_code rc;
    rc = qmckl_compute_c_vector_full(context,
                                      ctx->nucleus.num,
                                      ctx->jastrow.dim_c_vector,
                                      ctx->jastrow.type_nucl_num,
                                      ctx->jastrow.type_nucl_vector,
                                      ctx->jastrow.c_vector,
                                      ctx->jastrow.c_vector_full);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.c_vector_full_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_provide_lkpm_combined_index(qmckl_context context)
{

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.lkpm_combined_index_date) {

    /* Allocate array */
    if (ctx->jastrow.lkpm_combined_index == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = 4 * ctx->jastrow.dim_c_vector * sizeof(int64_t);
      int64_t* lkpm_combined_index = (int64_t*) qmckl_malloc(context, mem_info);

      if (lkpm_combined_index == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_lkpm_combined_index",
                               NULL);
      }
      ctx->jastrow.lkpm_combined_index = lkpm_combined_index;
    }

    qmckl_exit_code rc;
    rc = qmckl_compute_lkpm_combined_index(context,
                                           ctx->jastrow.cord_num,
                                           ctx->jastrow.dim_c_vector,
                                           ctx->jastrow.lkpm_combined_index);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.lkpm_combined_index_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_provide_tmp_c(qmckl_context context)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  qmckl_exit_code rc = QMCKL_SUCCESS;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.tmp_c_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.tmp_c != NULL) {
        rc = qmckl_free(context, ctx->jastrow.tmp_c);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_tmp_c",
                                 "Unable to free ctx->jastrow.tmp_c");
        }
        ctx->jastrow.tmp_c = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.tmp_c == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = (ctx->jastrow.cord_num) * (ctx->jastrow.cord_num + 1)
                      ,* ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num * sizeof(double);
      double* tmp_c = (double*) qmckl_malloc(context, mem_info);

      if (tmp_c == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_tmp_c",
                               NULL);
      }
      ctx->jastrow.tmp_c = tmp_c;
    }


    /* Choose the correct compute function (depending on offload type) */
#ifdef HAVE_HPC
    const bool gpu_offload = ctx->jastrow.gpu_offload;
#else
    const bool gpu_offload = false;
#endif

    if (gpu_offload) {
#ifdef HAVE_CUBLAS_OFFLOAD
      rc = qmckl_compute_tmp_c_cublas_offload(context,
                                              ctx->jastrow.cord_num,
                                              ctx->electron.num,
                                              ctx->nucleus.num,
                                              ctx->electron.walker.num,
                                              ctx->jastrow.een_rescaled_e,
                                              ctx->jastrow.een_rescaled_n,
                                              ctx->jastrow.tmp_c);
#elif HAVE_OPENACC_OFFLOAD
      rc = qmckl_compute_tmp_c_acc_offload(context,
                                           ctx->jastrow.cord_num,
                                           ctx->electron.num,
                                           ctx->nucleus.num,
                                           ctx->electron.walker.num,
                                           ctx->jastrow.een_rescaled_e,
                                           ctx->jastrow.een_rescaled_n,
                                           ctx->jastrow.tmp_c);
#elif HAVE_OPENMP_OFFLOAD
      rc = qmckl_compute_tmp_c_omp_offload(context,
                                           ctx->jastrow.cord_num,
                                           ctx->electron.num,
                                           ctx->nucleus.num,
                                           ctx->electron.walker.num,
                                           ctx->jastrow.een_rescaled_e,
                                           ctx->jastrow.een_rescaled_n,
                                           ctx->jastrow.tmp_c);
#else
      rc = QMCKL_FAILURE;
#endif
    } else {
      rc = qmckl_compute_tmp_c(context,
                               ctx->jastrow.cord_num,
                               ctx->electron.num,
                               ctx->nucleus.num,
                               ctx->electron.walker.num,
                               ctx->jastrow.een_rescaled_e,
                               ctx->jastrow.een_rescaled_n,
                               ctx->jastrow.tmp_c);
    }


    ctx->jastrow.tmp_c_date = ctx->date;
  }

  return rc;
}

qmckl_exit_code qmckl_provide_dtmp_c(qmckl_context context)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }
  
  qmckl_exit_code rc;
  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.dtmp_c_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.dtmp_c != NULL) {
        rc = qmckl_free(context, ctx->jastrow.dtmp_c);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_dtmp_c",
                                 "Unable to free ctx->jastrow.dtmp_c");
        }
        ctx->jastrow.dtmp_c = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.dtmp_c == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = (ctx->jastrow.cord_num) * (ctx->jastrow.cord_num + 1)
                      ,* 4 * ctx->electron.num * ctx->nucleus.num * ctx->electron.walker.num * sizeof(double);
      double* dtmp_c = (double*) qmckl_malloc(context, mem_info);

      if (dtmp_c == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_dtmp_c",
                               NULL);
      }
      ctx->jastrow.dtmp_c = dtmp_c;
    }


#ifdef HAVE_HPC
    const bool gpu_offload = ctx->jastrow.gpu_offload;
#else
    const bool gpu_offload = false;
#endif

    if (gpu_offload) {
#ifdef HAVE_CUBLAS_OFFLOAD
      rc = qmckl_compute_dtmp_c_cublas_offload(context,
                                            ctx->jastrow.cord_num,
                                            ctx->electron.num,
                                            ctx->nucleus.num,
                                            ctx->electron.walker.num,
                                            ctx->jastrow.een_rescaled_e_deriv_e,
                                            ctx->jastrow.een_rescaled_n,
                                            ctx->jastrow.dtmp_c);
#elif HAVE_OPENACC_OFFLOAD
      rc = qmckl_compute_dtmp_c_acc_offload(context,
                                            ctx->jastrow.cord_num,
                                            ctx->electron.num,
                                            ctx->nucleus.num,
                                            ctx->electron.walker.num,
                                            ctx->jastrow.een_rescaled_e_deriv_e,
                                            ctx->jastrow.een_rescaled_n,
                                            ctx->jastrow.dtmp_c);
#elif HAVE_OPENMP_OFFLOAD
      rc = qmckl_compute_dtmp_c_omp_offload(context,
                                            ctx->jastrow.cord_num,
                                            ctx->electron.num,
                                            ctx->nucleus.num,
                                            ctx->electron.walker.num,
                                            ctx->jastrow.een_rescaled_e_deriv_e,
                                            ctx->jastrow.een_rescaled_n,
                                            ctx->jastrow.dtmp_c);
#else
      rc = QMCKL_FAILURE;
#endif
    } else {
        rc = qmckl_compute_dtmp_c(context,
                                ctx->jastrow.cord_num,
                                ctx->electron.num,
                                ctx->nucleus.num,
                                ctx->electron.walker.num,
                                ctx->jastrow.een_rescaled_e_deriv_e,
                                ctx->jastrow.een_rescaled_n,
                                ctx->jastrow.dtmp_c);
    }

    if (rc != QMCKL_SUCCESS) {
      return rc;
    }


    ctx->jastrow.dtmp_c_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute dim_c_vector
   :PROPERTIES:
   :Name:     qmckl_compute_dim_c_vector
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_dim_c_vector_args
    | Variable        | Type            | In/Out | Description                       |
    |-----------------+-----------------+--------+-----------------------------------|
    | ~context~       | ~qmckl_context~ | in     | Global state                      |
    | ~cord_num~      | ~int64_t~       | in     | Order of polynomials              |
    | ~dim_c_vector~ | ~int64_t~       | out    | dimension of c_vector_full table |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_dim_c_vector_f( &
     context, cord_num, dim_c_vector) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: cord_num
  integer*8             , intent(out) :: dim_c_vector
  double precision                    :: x
  integer*8                           :: i, a, k, l, p, lmax

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  dim_c_vector = 0

  do p = 2, cord_num
    do k = p - 1, 0, -1
      if (k .ne. 0) then
        lmax = p - k
      else
        lmax = p - k - 2
      endif
      do l = lmax, 0, -1
        if (iand(p - k - l, 1_8) == 1) cycle
        dim_c_vector = dim_c_vector + 1
      end do
    end do
  end do

end function qmckl_compute_dim_c_vector_f
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_dim_c_vector (
      const qmckl_context context,
      const int64_t cord_num,
      int64_t* const dim_c_vector){

  int         lmax;


  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
    return QMCKL_INVALID_ARG_2;
  }

  *dim_c_vector = 0;

  for (int p=2; p <= cord_num; ++p){
    for (int k=p-1; k >= 0; --k) {
      if (k != 0) {
        lmax = p - k;
      } else {
        lmax = p - k - 2;
      }
      for (int l = lmax; l >= 0; --l) {
        if ( ((p - k - l) & 1)==1) continue;
        *dim_c_vector=*dim_c_vector+1;
      }
    }
  }

  return QMCKL_SUCCESS;
}
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_dim_c_vector_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_dim_c_vector (
          const qmckl_context context,
          const int64_t cord_num,
          int64_t* const dim_c_vector );
    #+end_src

*** Compute c_vector_full
   :PROPERTIES:
   :Name:     qmckl_compute_c_vector_full
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_c_vector_full_args
    | Variable           | Type                                   | In/Out | Description                  |
    |--------------------+----------------------------------------+--------+------------------------------|
    | ~context~          | ~qmckl_context~                        | in     | Global state                 |
    | ~nucl_num~         | ~int64_t~                              | in     | Number of atoms              |
    | ~dim_c_vector~     | ~int64_t~                              | in     | dimension of cord full table |
    | ~type_nucl_num~    | ~int64_t~                              | in     | dimension of cord full table |
    | ~type_nucl_vector~ | ~int64_t[nucl_num]~                    | in     | dimension of cord full table |
    | ~c_vector~         | ~double[dim_c_vector][type_nucl_num]~ | in     | dimension of cord full table |
    | ~c_vector_full~    | ~double[dim_c_vector][nucl_num]~      | out    | Full list of coefficients    |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_c_vector_full_doc_f( &
     context, nucl_num, dim_c_vector, type_nucl_num,  &
     type_nucl_vector, c_vector, c_vector_full) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: dim_c_vector
  integer*8             , intent(in)  :: type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  double precision      , intent(in)  :: c_vector(type_nucl_num, dim_c_vector)
  double precision      , intent(out) :: c_vector_full(nucl_num,dim_c_vector)
  double precision                    :: x
  integer*8                           :: i, a, k, l, nw

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (type_nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (dim_c_vector < 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif


  do a = 1, nucl_num
    c_vector_full(a,1:dim_c_vector) = c_vector(type_nucl_vector(a),1:dim_c_vector)
  end do

end function qmckl_compute_c_vector_full_doc_f
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_factor_c_vector_full_args,rettyp=get_value("CRetType"),fname="qmckl_compute_c_vector_full_doc")

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_c_vector_full_doc &
	(context, nucl_num, dim_c_vector, type_nucl_num, type_nucl_vector, c_vector, c_vector_full) &
	bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: dim_c_vector
      integer (c_int64_t) , intent(in)  , value :: type_nucl_num
      integer (c_int64_t) , intent(in)          :: type_nucl_vector(nucl_num)
      real    (c_double ) , intent(in)          :: c_vector(type_nucl_num,dim_c_vector)
      real    (c_double ) , intent(out)         :: c_vector_full(nucl_num,dim_c_vector)

      integer(c_int32_t), external :: qmckl_compute_c_vector_full_doc_f
      info = qmckl_compute_c_vector_full_doc_f &
	     (context, nucl_num, dim_c_vector, type_nucl_num, type_nucl_vector, c_vector, c_vector_full)

    end function qmckl_compute_c_vector_full_doc
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_c_vector_full_hpc (
	  const qmckl_context context,
	  const int64_t nucl_num,
	  const int64_t dim_c_vector,
	  const int64_t type_nucl_num,
	  const int64_t* type_nucl_vector,
	  const double* c_vector,
	  double* const c_vector_full ) {

  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (nucl_num <= 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (type_nucl_num <= 0) {
     return QMCKL_INVALID_ARG_4;
  }

  if (dim_c_vector < 0) {
     return QMCKL_INVALID_ARG_5;
  }

  for (int i=0; i < dim_c_vector; ++i) {
    for (int a=0; a < nucl_num; ++a){
      c_vector_full[a + i*nucl_num] = c_vector[(type_nucl_vector[a]-1)+i*type_nucl_num];
    }
  }

  return QMCKL_SUCCESS;
  }
    #+end_src


#   #+CALL: generate_c_header(table=qmckl_factor_c_vector_full_args,rettyp=get_value("CRetType"),fname="qmckl_compute_c_vector_full_doc")

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_c_vector_full (
	  const qmckl_context context,
	  const int64_t nucl_num,
	  const int64_t dim_c_vector,
	  const int64_t type_nucl_num,
	  const int64_t* type_nucl_vector,
	  const double* c_vector,
	  double* const c_vector_full );
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org
    qmckl_exit_code qmckl_compute_c_vector_full_doc (
	  const qmckl_context context,
	  const int64_t nucl_num,
	  const int64_t dim_c_vector,
	  const int64_t type_nucl_num,
	  const int64_t* type_nucl_vector,
	  const double* c_vector,
	  double* const c_vector_full );
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org
    qmckl_exit_code qmckl_compute_c_vector_full_hpc (
	  const qmckl_context context,
	  const int64_t nucl_num,
	  const int64_t dim_c_vector,
	  const int64_t type_nucl_num,
	  const int64_t* type_nucl_vector,
	  const double* c_vector,
	  double* const c_vector_full );
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_c_vector_full (
	  const qmckl_context context,
	  const int64_t nucl_num,
	  const int64_t dim_c_vector,
	  const int64_t type_nucl_num,
	  const int64_t* type_nucl_vector,
	  const double* c_vector,
	  double* const c_vector_full ) {

    #ifdef HAVE_HPC
      return qmckl_compute_c_vector_full_hpc(context, nucl_num, dim_c_vector, type_nucl_num, type_nucl_vector, c_vector, c_vector_full);
    #else
      return qmckl_compute_c_vector_full_doc(context, nucl_num, dim_c_vector, type_nucl_num, type_nucl_vector, c_vector, c_vector_full);
    #endif
    }
    #+end_src


*** Compute lkpm_combined_index
   :PROPERTIES:
   :Name:     qmckl_compute_lkpm_combined_index
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_lkpm_combined_index_args
    | Variable              | Type                        | In/Out | Description                   |
    |-----------------------+-----------------------------+--------+-------------------------------|
    | ~context~             | ~qmckl_context~             | in     | Global state                  |
    | ~cord_num~            | ~int64_t~                   | in     | Order of polynomials          |
    | ~dim_c_vector~       | ~int64_t~                   | in     | dimension of cord full table  |
    | ~lkpm_combined_index~ | ~int64_t[4][dim_c_vector]~ | out    | Full list of combined indices |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_lkpm_combined_index_f( &
     context, cord_num, dim_c_vector,  lkpm_combined_index) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: cord_num
  integer*8             , intent(in)  :: dim_c_vector
  integer*8             , intent(out) :: lkpm_combined_index(dim_c_vector, 4)
  double precision                    :: x
  integer*8                           :: i, a, k, l, kk, p, lmax, m

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (dim_c_vector < 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif


  kk = 0
  do p = 2, cord_num
    do k = p - 1, 0, -1
      if (k .ne. 0) then
        lmax = p - k
      else
        lmax = p - k - 2
      end if
      do l = lmax, 0, -1
        if (iand(p - k - l, 1_8) .eq. 1) cycle
        m = (p - k - l)/2
        kk = kk + 1
        lkpm_combined_index(kk, 1) = l
        lkpm_combined_index(kk, 2) = k
        lkpm_combined_index(kk, 3) = p
        lkpm_combined_index(kk, 4) = m
      end do
    end do
  end do

end function qmckl_compute_lkpm_combined_index_f
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_lkpm_combined_index (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t dim_c_vector,
      int64_t* const lkpm_combined_index ) {

  int kk, lmax, m;

  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (dim_c_vector < 0) {
     return QMCKL_INVALID_ARG_3;
  }

/*
*/
  kk = 0;
  for (int p = 2; p <= cord_num; ++p) {
    for (int k=(p-1); k >= 0; --k) {
      if (k != 0) {
        lmax = p - k;
      } else {
        lmax = p - k - 2;
      }
      for (int l=lmax; l >= 0; --l) {
        if (((p - k - l) & 1) == 1) continue;
        m = (p - k - l)/2;
        lkpm_combined_index[kk                  ] = l;
        lkpm_combined_index[kk +   dim_c_vector] = k;
        lkpm_combined_index[kk + 2*dim_c_vector] = p;
        lkpm_combined_index[kk + 3*dim_c_vector] = m;
        kk = kk + 1;
      }
    }
  }

  return QMCKL_SUCCESS;
}
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_lkpm_combined_index_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_lkpm_combined_index (
          const qmckl_context context,
          const int64_t cord_num,
          const int64_t dim_c_vector,
          int64_t* const lkpm_combined_index );
    #+end_src


*** Compute tmp_c
   :PROPERTIES:
   :Name:     qmckl_compute_tmp_c
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_tmp_c_args
    | Variable         | Type                                                             | In/Out | Description                       |
    |------------------+------------------------------------------------------------------+--------+-----------------------------------|
    | ~context~        | ~qmckl_context~                                                  | in     | Global state                      |
    | ~cord_num~       | ~int64_t~                                                        | in     | Order of polynomials              |
    | ~elec_num~       | ~int64_t~                                                        | in     | Number of electrons               |
    | ~nucl_num~       | ~int64_t~                                                        | in     | Number of nucleii                 |
    | ~walk_num~       | ~int64_t~                                                        | in     | Number of walkers                 |
    | ~een_rescaled_e~ | ~double[walk_num][0:cord_num][elec_num][elec_num]~               | in     | Electron-electron rescaled factor |
    | ~een_rescaled_n~ | ~double[walk_num][0:cord_num][nucl_num][elec_num]~               | in     | Electron-nucleus rescaled factor  |
    | ~tmp_c~          | ~double[walk_num][0:cord_num-1][0:cord_num][nucl_num][elec_num]~ | out    | vector of non-zero coefficients   |

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_tmp_c (const qmckl_context context,
                                     const int64_t cord_num,
                                     const int64_t elec_num,
                                     const int64_t nucl_num,
                                     const int64_t walk_num,
                                     const double* een_rescaled_e,
                                     const double* een_rescaled_n,
                                     double* const tmp_c )
{
#ifdef HAVE_HPC
  return qmckl_compute_tmp_c_hpc(context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e, een_rescaled_n, tmp_c);
#else
  return qmckl_compute_tmp_c_doc(context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e, een_rescaled_n, tmp_c);
#endif
}
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_tmp_c_args,rettyp=get_value("CRetType"),fname="qmckl_compute_tmp_c")

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_tmp_c (
          const qmckl_context context,
          const int64_t cord_num,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t walk_num,
          const double* een_rescaled_e,
          const double* een_rescaled_n,
          double* const tmp_c );
    #+end_src

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_tmp_c_doc_f( &
     context, cord_num, elec_num, nucl_num, &
     walk_num, een_rescaled_e, een_rescaled_n, tmp_c) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: cord_num
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: walk_num
  double precision      , intent(in)  :: een_rescaled_e(elec_num, elec_num, 0:cord_num, walk_num)
  double precision      , intent(in)  :: een_rescaled_n(elec_num, nucl_num, 0:cord_num, walk_num)
  double precision      , intent(out) :: tmp_c(elec_num, nucl_num,0:cord_num, 0:cord_num-1, walk_num)
  double precision                    :: x
  integer*8                           :: i, j, a, l, kk, p, lmax, nw
  character                           :: TransA, TransB
  double precision                    :: alpha, beta
  integer*8                           :: M, N, K, LDA, LDB, LDC

  TransA = 'N'
  TransB = 'N'
  alpha = 1.0d0
  beta  = 0.0d0

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  M = elec_num
  N = nucl_num*(cord_num + 1)
  K = elec_num
  LDA = size(een_rescaled_e,1)
  LDB = size(een_rescaled_n,1)
  LDC = size(tmp_c,1)

  do nw=1, walk_num
  do i=0, cord_num-1
  info = qmckl_dgemm(context, TransA, TransB, M, N, K, alpha,     &
                     een_rescaled_e(1,1,i,nw),LDA*1_8,                     &
                     een_rescaled_n(1,1,0,nw),LDB*1_8,                     &
                     beta,                                       &
                     tmp_c(1,1,0,i,nw),LDC)
  end do
  end do

end function qmckl_compute_tmp_c_doc_f
    #+end_src

    #+begin_src c :tangle (eval h_private_func) :comments org
qmckl_exit_code qmckl_compute_tmp_c_doc (
          const qmckl_context context,
          const int64_t cord_num,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t walk_num,
          const double* een_rescaled_e,
          const double* een_rescaled_n,
          double* const tmp_c );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_factor_tmp_c_args,rettyp=get_value("FRetType"),fname="qmckl_compute_tmp_c_doc")

#+RESULTS:
#+begin_src f90 :tangle (eval f) :comments org :exports none
integer(c_int32_t) function qmckl_compute_tmp_c_doc &
    (context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e, een_rescaled_n, tmp_c) &
    bind(C) result(info)

  use, intrinsic :: iso_c_binding
  implicit none

  integer (c_int64_t) , intent(in)  , value :: context
  integer (c_int64_t) , intent(in)  , value :: cord_num
  integer (c_int64_t) , intent(in)  , value :: elec_num
  integer (c_int64_t) , intent(in)  , value :: nucl_num
  integer (c_int64_t) , intent(in)  , value :: walk_num
  real    (c_double ) , intent(in)          :: een_rescaled_e(elec_num,elec_num,0:cord_num,walk_num)
  real    (c_double ) , intent(in)          :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)
  real    (c_double ) , intent(out)         :: tmp_c(elec_num,nucl_num,0:cord_num,0:cord_num-1,walk_num)

  integer(c_int32_t), external :: qmckl_compute_tmp_c_doc_f
  info = qmckl_compute_tmp_c_doc_f &
         (context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e, een_rescaled_n, tmp_c)

end function qmckl_compute_tmp_c_doc
#+end_src

**** CPU                                                           :noexport:

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_tmp_c_hpc (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e,
      const double* een_rescaled_n,
      double* const tmp_c ) {

  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
    return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
    return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
    return QMCKL_INVALID_ARG_4;
  }

  if (walk_num <= 0) {
    return QMCKL_INVALID_ARG_5;
  }

  qmckl_exit_code info = QMCKL_SUCCESS;

  const char  TransA = 'N';
  const char  TransB = 'N';
  const double alpha = 1.0;
  const double beta  = 0.0;

  const int64_t M = elec_num;
  const int64_t N = nucl_num*(cord_num + 1);
  const int64_t K = elec_num;

  const int64_t LDA = elec_num;
  const int64_t LDB = elec_num;
  const int64_t LDC = elec_num;

  const int64_t af = elec_num*elec_num;
  const int64_t bf = elec_num*nucl_num*(cord_num+1);
  const int64_t cf = bf;

#ifdef HAVE_OPENMP
#pragma omp parallel for collapse(2)
#endif
  for (int64_t nw=0; nw < walk_num; ++nw) {
    for (int64_t i=0; i<cord_num; ++i){
      info = qmckl_dgemm(context, TransA, TransB, M, N, K, alpha,
                         &(een_rescaled_e[af*(i+nw*(cord_num+1))]), LDA,
                         &(een_rescaled_n[bf*nw]), LDB, beta,
                         &(tmp_c[cf*(i+nw*cord_num)]), LDC);
    }
  }

  return info;
}
    #+end_src



    #+CALL: generate_c_header(table=qmckl_factor_tmp_c_args,rettyp=get_value("CRetType"),fname="qmckl_compute_tmp_c")

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
qmckl_exit_code qmckl_compute_tmp_c (
          const qmckl_context context,
          const int64_t cord_num,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t walk_num,
          const double* een_rescaled_e,
          const double* een_rescaled_n,
          double* const tmp_c );
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_tmp_c_args,rettyp=get_value("CRetType"),fname="qmckl_compute_tmp_c_doc")

    #+RESULTS:
    #+begin_src c :tangle (eval h_private_func) :comments org
qmckl_exit_code qmckl_compute_tmp_c_doc (
          const qmckl_context context,
          const int64_t cord_num,
          const int64_t elec_num,
          const int64_t nucl_num,
          const int64_t walk_num,
          const double* een_rescaled_e,
          const double* een_rescaled_n,
          double* const tmp_c );
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_tmp_c_args,rettyp=get_value("CRetType"),fname="qmckl_compute_tmp_c_hpc")

    #+RESULTS:

    #+begin_src c :tangle (eval h_private_func) :comments org
qmckl_exit_code qmckl_compute_tmp_c_hpc (const qmckl_context context,
                                         const int64_t cord_num,
                                         const int64_t elec_num,
                                         const int64_t nucl_num,
                                         const int64_t walk_num,
                                         const double* een_rescaled_e,
                                         const double* een_rescaled_n,
                                         double* const tmp_c );
    #+end_src

**** OpenACC offload                                               :noexport:

     #+begin_src c :comments org :tangle (eval c) :noweb yes
#ifdef HAVE_OPENACC_OFFLOAD
qmckl_exit_code
qmckl_compute_tmp_c_acc_offload (const qmckl_context context,
                                 const int64_t cord_num,
                                 const int64_t elec_num,
                                 const int64_t nucl_num,
                                 const int64_t walk_num,
                                 const double* een_rescaled_e,
                                 const double* een_rescaled_n,
                                 double* const tmp_c )
{

  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
    return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
    return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
    return QMCKL_INVALID_ARG_4;
  }

  // Compute array access strides:
  // For tmp_c...
  const int64_t stride_k_c  = elec_num;
  const int64_t stride_j_c  = stride_k_c * nucl_num;
  const int64_t stride_i_c  = stride_j_c * (cord_num+1);
  const int64_t stride_nw_c = stride_i_c * cord_num;
  // For een_rescaled_e...
  const int64_t stride_m_e  = elec_num;
  const int64_t stride_i_e  = stride_m_e * elec_num;
  const int64_t stride_nw_e = stride_i_e * (cord_num+1);
  // For een_rescaled_n...
  const int64_t stride_k_n  = elec_num;
  const int64_t stride_j_n  = stride_k_n * nucl_num;
  const int64_t stride_nw_n = stride_j_n * (cord_num+1);

  const int64_t size_tmp_c = elec_num*nucl_num*(cord_num+1)*cord_num*walk_num;
  const int64_t size_e = walk_num*(cord_num+1)*elec_num*elec_num;
  const int64_t size_n = walk_num*(cord_num+1)*nucl_num*elec_num;

  #pragma acc parallel copyout(tmp_c [0:size_tmp_c]) copyin(een_rescaled_e[0:size_e], een_rescaled_n[0:size_n])
  {
#pragma acc loop independent gang worker vector collapse(5)
    for (int nw=0; nw < walk_num; ++nw) {
      for (int i=0; i<cord_num; ++i){

        // Replacement for single DGEMM
        for (int j=0; j<cord_num+1; j++) {
          for (int k=0; k<nucl_num; k++) {
            for (int l=0; l<elec_num; l++) {

              // Single reduction
              tmp_c[l + k*stride_k_c + j*stride_j_c + i*stride_i_c + nw*stride_nw_c] = 0.;
              for (int m=0; m<elec_num; m++) {
                tmp_c[l + k*stride_k_c + j*stride_j_c + i*stride_i_c + nw*stride_nw_c] =
                tmp_c[l + k*stride_k_c + j*stride_j_c + i*stride_i_c + nw*stride_nw_c] +
                een_rescaled_e[l + m*stride_m_e + i*stride_i_e + nw*stride_nw_e] *
                een_rescaled_n[m + k*stride_k_n + j*stride_j_n + nw*stride_nw_n];
            }
          }
        }
      }
    }
  }
  }

  return QMCKL_SUCCESS;
}
#endif
     #+end_src

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
#ifdef HAVE_OPENACC_OFFLOAD
qmckl_exit_code
qmckl_compute_tmp_c_acc_offload (const qmckl_context context,
                                 const int64_t cord_num,
                                 const int64_t elec_num,
                                 const int64_t nucl_num,
                                 const int64_t walk_num,
                                 const double* een_rescaled_e,
                                 const double* een_rescaled_n,
                                 double* const tmp_c );
#endif
     #+end_src

**** OpenMP offload                                                :noexport:

     #+begin_src c :comments org :tangle (eval c) :noweb yes
#ifdef HAVE_OPENMP_OFFLOAD
qmckl_exit_code
qmckl_compute_tmp_c_omp_offload (const qmckl_context context,
                                 const int64_t cord_num,
                                 const int64_t elec_num,
                                 const int64_t nucl_num,
                                 const int64_t walk_num,
                                 const double* een_rescaled_e,
                                 const double* een_rescaled_n,
                                 double* const tmp_c )
{

  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
    return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
    return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
    return QMCKL_INVALID_ARG_4;
  }

  // Compute array access strides:
  // For tmp_c...
  const int64_t stride_k_c  = elec_num;
  const int64_t stride_j_c  = stride_k_c * nucl_num;
  const int64_t stride_i_c  = stride_j_c * (cord_num+1);
  const int64_t stride_nw_c = stride_i_c * cord_num;
  // For een_rescaled_e...
  const int64_t stride_m_e  = elec_num;
  const int64_t stride_i_e  = stride_m_e * elec_num;
  const int64_t stride_nw_e = stride_i_e * (cord_num+1);
  // For een_rescaled_n...
  const int64_t stride_k_n  = elec_num;
  const int64_t stride_j_n  = stride_k_n * nucl_num;
  const int64_t stride_nw_n = stride_j_n * (cord_num+1);

  const int64_t size_tmp_c = elec_num*nucl_num*(cord_num+1)*cord_num*walk_num;
  const int64_t size_e = walk_num*(cord_num+1)*elec_num*elec_num;
  const int64_t size_n = walk_num*(cord_num+1)*nucl_num*elec_num;


  // WARNING This implementation seems unomptimized
  #pragma omp target map(from:tmp_c[0:size_tmp_c]) map(to:een_rescaled_e[0:size_e], een_rescaled_n[0:size_n])
  {
  #pragma omp teams distribute parallel for collapse(5)
    for (int nw=0; nw < walk_num; ++nw) {
      for (int i=0; i<cord_num; ++i){

        // Replacement for single DGEMM
        for (int j=0; j<cord_num+1; j++) {
          for (int k=0; k<nucl_num; k++) {
            for (int l=0; l<elec_num; l++) {

              // Single reduction
              tmp_c[l + k*stride_k_c + j*stride_j_c + i*stride_i_c + nw*stride_nw_c] = 0.;
              for (int m=0; m<elec_num; m++) {
                tmp_c[l + k*stride_k_c + j*stride_j_c + i*stride_i_c + nw*stride_nw_c] =
                  tmp_c[l + k*stride_k_c + j*stride_j_c + i*stride_i_c + nw*stride_nw_c] +
                  een_rescaled_e[l + m*stride_m_e + i*stride_i_e + nw*stride_nw_e] *
                  een_rescaled_n[m + k*stride_k_n + j*stride_j_n + nw*stride_nw_n];
              }
            }
          }
        }
      }
    }
  }

  return QMCKL_SUCCESS;
}
#endif
     #+end_src

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
#ifdef HAVE_OPENMP_OFFLOAD
qmckl_exit_code
qmckl_compute_tmp_c_omp_offload (const qmckl_context context,
                                 const int64_t cord_num,
                                 const int64_t elec_num,
                                 const int64_t nucl_num,
                                 const int64_t walk_num,
                                 const double* een_rescaled_e,
                                 const double* een_rescaled_n,
                                 double* const tmp_c );
#endif
     #+end_src

**** cuBLAS offload                                                :noexport:

#+begin_src c :comments org :tangle (eval c) :noweb yes
#ifdef HAVE_CUBLAS_OFFLOAD
qmckl_exit_code
qmckl_compute_tmp_c_cublas_offload (const qmckl_context context,
                                    const int64_t cord_num,
                                    const int64_t elec_num,
                                    const int64_t nucl_num,
                                    const int64_t walk_num,
                                    const double* een_rescaled_e,
                                    const double* een_rescaled_n,
                                    double* const tmp_c )
{

  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
    return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
    return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
    return QMCKL_INVALID_ARG_4;
  }

  //cuBLAS initialization
  cublasHandle_t handle;
  if (cublasCreate(&handle) != CUBLAS_STATUS_SUCCESS)
  {
    fprintf(stdout, "CUBLAS initialization failed!\n");
    exit(EXIT_FAILURE);
  }

  const double alpha = 1.0;
  const double beta  = 0.0;

  const int64_t M = elec_num;
  const int64_t N = nucl_num*(cord_num + 1);
  const int64_t K = elec_num;

  const int64_t LDA = elec_num;
  const int64_t LDB = elec_num;
  const int64_t LDC = elec_num;

  const int64_t af = elec_num*elec_num;
  const int64_t bf = elec_num*nucl_num*(cord_num+1);
  const int64_t cf = bf;

  #pragma omp target enter data map(to:een_rescaled_e[0:elec_num*elec_num*(cord_num+1)*walk_num],een_rescaled_n[0:M*N*walk_num],tmp_c[0:elec_num*nucl_num*(cord_num+1)*cord_num*walk_num])
  #pragma omp target data use_device_ptr(een_rescaled_e,een_rescaled_n,tmp_c)
  {
  for (int nw=0; nw < walk_num; ++nw) {

    // /!\  cublasError needs to be checked and return QMCKL_FAILURE if it fails
    int cublasError = cublasDgemmStridedBatched(handle, CUBLAS_OP_N, CUBLAS_OP_N, M, N, K, &alpha,
                                    &(een_rescaled_e[nw*(cord_num+1)]),
                                    LDA, af,
                                    &(een_rescaled_n[bf*nw]),
                                    LDB, 0,
                                    &beta,
                                    &(tmp_c[nw*cord_num]),
                                    LDC, cf, cord_num);
  }
  }
  #pragma omp target exit data map(from:tmp_c[0:elec_num*nucl_num*(cord_num+1)*cord_num*walk_num])

  cublasDestroy(handle);
  return QMCKL_SUCCESS;
  }
#endif

#+end_src


    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
#ifdef HAVE_CUBLAS_OFFLOAD
qmckl_exit_code
qmckl_compute_tmp_c_cublas_offload (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e,
      const double* een_rescaled_n,
      double* const tmp_c );
#endif
     #+end_src

*** Compute dtmp_c
   :PROPERTIES:
   :Name:     qmckl_compute_dtmp_c
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_dtmp_c_args
    | Variable                 | Type                                                             | In/Out | Description                                   |
    |--------------------------+------------------------------------------------------------------+--------+-----------------------------------------------|
    | ~context~                | ~qmckl_context~                                                  | in     | Global state                                  |
    | ~cord_num~               | ~int64_t~                                                        | in     | Order of polynomials                          |
    | ~elec_num~               | ~int64_t~                                                        | in     | Number of electrons                           |
    | ~nucl_num~               | ~int64_t~                                                        | in     | Number of nucleii                             |
    | ~walk_num~               | ~int64_t~                                                        | in     | Number of walkers                             |
    | ~een_rescaled_e_deriv_e~ | ~double[walk_num][0:cord_num][elec_num][4][elec_num]~            | in     | Electron-electron rescaled factor derivatives |
    | ~een_rescaled_n~         | ~double[walk_num][0:cord_num][nucl_num][elec_num]~               | in     | Electron-nucleus rescaled factor              |
    | ~dtmp_c~                 | ~double[walk_num][0:cord_num-1][0:cord_num][nucl_num][elec_num]~ | out    | vector of non-zero coefficients               |


    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code
qmckl_compute_dtmp_c (const qmckl_context context,
                      const int64_t cord_num,
                      const int64_t elec_num,
                      const int64_t nucl_num,
                      const int64_t walk_num,
                      const double* een_rescaled_e_deriv_e,
                      const double* een_rescaled_n,
                      double* const dtmp_c );
     #+end_src

     #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code
qmckl_compute_dtmp_c (const qmckl_context context,
                      const int64_t cord_num,
                      const int64_t elec_num,
                      const int64_t nucl_num,
                      const int64_t walk_num,
                      const double* een_rescaled_e_deriv_e,
                      const double* een_rescaled_n,
                      double* const dtmp_c )
{
#ifdef HAVE_HPC
  return qmckl_compute_dtmp_c_hpc (context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e_deriv_e,
                                   een_rescaled_n, dtmp_c );
#else
  return qmckl_compute_dtmp_c_doc (context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e_deriv_e,
                                   een_rescaled_n, dtmp_c );
#endif
}
     #+end_src

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_dtmp_c_doc_f( &
     context, cord_num, elec_num, nucl_num, &
     walk_num, een_rescaled_e_deriv_e, een_rescaled_n, dtmp_c) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: cord_num
  integer*8             , intent(in)  :: elec_num
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: walk_num
  double precision      , intent(in)  :: een_rescaled_e_deriv_e(elec_num, 4, elec_num, 0:cord_num, walk_num)
  double precision      , intent(in)  :: een_rescaled_n(elec_num, nucl_num, 0:cord_num, walk_num)
  double precision      , intent(out) :: dtmp_c(elec_num, 4, nucl_num,0:cord_num, 0:cord_num-1,  walk_num)
  double precision                    :: x
  integer*8                           :: i, j, a, l, kk, p, lmax, nw, ii
  character                           :: TransA, TransB
  double precision                    :: alpha, beta
  integer*8                           :: M, N, K, LDA, LDB, LDC

  TransA = 'N'
  TransB = 'N'
  alpha = 1.0d0
  beta  = 0.0d0

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  M = 4*elec_num
  N = nucl_num*(cord_num + 1)
  K = elec_num
  LDA = 4*size(een_rescaled_e_deriv_e,1)
  LDB = size(een_rescaled_n,1)
  LDC = 4*size(dtmp_c,1)

  do nw=1, walk_num
     do i=0, cord_num-1
        info = qmckl_dgemm(context,TransA, TransB, M, N, K, alpha,  &
             een_rescaled_e_deriv_e(1,1,1,i,nw),LDA*1_8,            &
             een_rescaled_n(1,1,0,nw),LDB*1_8,                      &
             beta,                                                  &
             dtmp_c(1,1,1,0,i,nw),LDC)
     end do
  end do

end function qmckl_compute_dtmp_c_doc_f
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_factor_dtmp_c_args,rettyp=get_value("FRetType"),fname="qmckl_compute_dtmp_c_doc")

#+RESULTS:
#+begin_src f90 :tangle (eval f) :comments org :exports none
integer(c_int32_t) function qmckl_compute_dtmp_c_doc &
    (context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e_deriv_e, een_rescaled_n, dtmp_c) &
    bind(C) result(info)

  use, intrinsic :: iso_c_binding
  implicit none

  integer (c_int64_t) , intent(in)  , value :: context
  integer (c_int64_t) , intent(in)  , value :: cord_num
  integer (c_int64_t) , intent(in)  , value :: elec_num
  integer (c_int64_t) , intent(in)  , value :: nucl_num
  integer (c_int64_t) , intent(in)  , value :: walk_num
  real    (c_double ) , intent(in)          :: een_rescaled_e_deriv_e(elec_num,4,elec_num,0:cord_num,walk_num)
  real    (c_double ) , intent(in)          :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)
  real    (c_double ) , intent(out)         :: dtmp_c(elec_num,nucl_num,0:cord_num,0:cord_num-1,walk_num)

  integer(c_int32_t), external :: qmckl_compute_dtmp_c_doc_f
  info = qmckl_compute_dtmp_c_doc_f &
         (context, cord_num, elec_num, nucl_num, walk_num, een_rescaled_e_deriv_e, een_rescaled_n, dtmp_c)

end function qmckl_compute_dtmp_c_doc
#+end_src

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_compute_dtmp_c_doc (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c );
     #+end_src

**** CPU                                                           :noexport:

     #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code
qmckl_compute_dtmp_c_hpc (const qmckl_context context,
                          const int64_t cord_num,
                          const int64_t elec_num,
                          const int64_t nucl_num,
                          const int64_t walk_num,
                          const double* een_rescaled_e_deriv_e,
                          const double* een_rescaled_n,
                          double* const dtmp_c )
{

  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
     return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
     return QMCKL_INVALID_ARG_4;
  }

  if (walk_num <= 0) {
     return QMCKL_INVALID_ARG_5;
  }

  qmckl_exit_code  info = QMCKL_SUCCESS;

  const char  TransA = 'N';
  const char  TransB = 'N';
  const double alpha = 1.0;
  const double beta  = 0.0;

  const int64_t M = 4*elec_num;
  const int64_t N = nucl_num*(cord_num + 1);
  const int64_t K = elec_num;

  const int64_t LDA = 4*elec_num;
  const int64_t LDB = elec_num;
  const int64_t LDC = 4*elec_num;

  const int64_t af = elec_num*elec_num*4;
  const int64_t bf = elec_num*nucl_num*(cord_num+1);
  const int64_t cf = elec_num*4*nucl_num*(cord_num+1);

#ifdef HAVE_OPENMP
#pragma omp parallel for collapse(2)
#endif
  for (int64_t nw=0; nw < walk_num; ++nw) {
    for (int64_t i=0; i < cord_num; ++i) {
      info = qmckl_dgemm(context, TransA, TransB, M, N, K, alpha,
                         &(een_rescaled_e_deriv_e[af*(i+nw*(cord_num+1))]), LDA,
                         &(een_rescaled_n[bf*nw]), LDB, beta,
                         &(dtmp_c[cf*(i+nw*cord_num)]), LDC);
    }
  }

  return info;
}
     #+end_src

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_compute_dtmp_c_hpc (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c );
     #+end_src

**** OpenACC offload                                               :noexport:

     #+begin_src c :comments org :tangle (eval c) :noweb yes
#ifdef HAVE_OPENACC_OFFLOAD
qmckl_exit_code
qmckl_compute_dtmp_c_acc_offload (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c ) {

  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
     return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
     return QMCKL_INVALID_ARG_4;
  }

  // Compute strides...
  // For dtmp_c
  const int64_t stride_l_d  = elec_num;
  const int64_t stride_k_d  = stride_l_d * 4;
  const int64_t stride_j_d  = stride_k_d * nucl_num;
  const int64_t stride_i_d  = stride_j_d * (cord_num+1);
  const int64_t stride_nw_d = stride_i_d * cord_num;
  // For een_rescaled_e_deriv_e
  const int64_t stride_l_e  = elec_num;
  const int64_t stride_n_e  = stride_l_e * 4;
  const int64_t stride_i_e  = stride_n_e * elec_num;
  const int64_t stride_nw_e = stride_i_e * cord_num;
  // For een_rescaled_n
  const int64_t stride_k_n  = elec_num;
  const int64_t stride_j_n  = stride_k_n * nucl_num;
  const int64_t stride_nw_n = stride_j_n * (cord_num+1);

  const int64_t size_dtmp_c = walk_num*cord_num*(cord_num+1)*nucl_num*4*elec_num;
  const int64_t size_n = walk_num*(cord_num+1)*nucl_num*elec_num;
  const int64_t size_e = walk_num*(cord_num+1)*elec_num*4*elec_num;

  #pragma acc parallel copyout(dtmp_c [0:size_dtmp_c]) copyin(een_rescaled_e_deriv_e[0:size_e], een_rescaled_n[0:size_n])
  {
  #pragma acc loop independent gang worker vector collapse(6)
  for (int nw=0; nw < walk_num; nw++) {
    for (int i=0; i < cord_num; i++) {

      // Single DGEMM
      for(int j=0; j<cord_num+1; j++) {
        for(int k=0; k<nucl_num; k++) {
          for(int l=0; l<4; l++) {
            for(int m=0; m<elec_num; m++) {

              // Single reduction
              dtmp_c[m + l * stride_l_d + k * stride_k_d + j * stride_j_d + i * stride_i_d + nw * stride_nw_d] = 0.;
              for(int n=0; n<elec_num; n++){
                dtmp_c[m + l * stride_l_d + k * stride_k_d + j * stride_j_d + i * stride_i_d + nw * stride_nw_d] =
                dtmp_c[m + l * stride_l_d + k * stride_k_d + j * stride_j_d + i * stride_i_d + nw * stride_nw_d] +
                een_rescaled_e_deriv_e[m + l * stride_l_e +  n * stride_n_e + i * stride_i_e + nw * stride_nw_e] *
                een_rescaled_n[n + k * stride_k_n + j * stride_j_n + nw * stride_nw_n];
              }
            }
          }
        }
      }
    }
  }
  }

  return QMCKL_SUCCESS;
}
#endif
     #+end_src

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
#ifdef HAVE_OPENACC_OFFLOAD
    qmckl_exit_code qmckl_compute_dtmp_c_acc_offload (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c );
#endif
     #+end_src

**** OpenMP offload                                                :noexport:

     #+begin_src c :comments org :tangle (eval c) :noweb yes
#ifdef HAVE_OPENMP_OFFLOAD
qmckl_exit_code qmckl_compute_dtmp_c_omp_offload (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c ) {

  if (context == QMCKL_NULL_CONTEXT) {
     return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
     return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
     return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
     return QMCKL_INVALID_ARG_4;
  }

  // Compute strides...
  // For dtmp_c
  const int64_t stride_l_d  = elec_num;
  const int64_t stride_k_d  = stride_l_d * 4;
  const int64_t stride_j_d  = stride_k_d * nucl_num;
  const int64_t stride_i_d  = stride_j_d * (cord_num+1);
  const int64_t stride_nw_d = stride_i_d * cord_num;
  // For een_rescaled_e_deriv_e
  const int64_t stride_l_e  = elec_num;
  const int64_t stride_n_e  = stride_l_e * 4;
  const int64_t stride_i_e  = stride_n_e * elec_num;
  const int64_t stride_nw_e = stride_i_e * cord_num;
  // For een_rescaled_n
  const int64_t stride_k_n  = elec_num;
  const int64_t stride_j_n  = stride_k_n * nucl_num;
  const int64_t stride_nw_n = stride_j_n * (cord_num+1);


  const int64_t size_dtmp_c = walk_num*cord_num*(cord_num+1)*nucl_num*4*elec_num;
  const int64_t size_n = walk_num*(cord_num+1)*nucl_num*elec_num;
  const int64_t size_e = walk_num*(cord_num+1)*elec_num*4*elec_num;

  // WARNING This implementation seems unomptimized
  #pragma omp target map(from:dtmp_c[0:size_dtmp_c]) map(to:een_rescaled_e_deriv_e[0:size_e], een_rescaled_n[0:size_n])
  {

  #pragma omp teams distribute parallel for collapse(6)
  for (int nw=0; nw < walk_num; nw++) {
    for (int i=0; i < cord_num; i++) {

      // Single DGEMM
      for(int j=0; j<cord_num+1; j++) {
        for(int k=0; k<nucl_num; k++) {
          for(int l=0; l<4; l++) {
            for(int m=0; m<elec_num; m++) {

              // Single reduction
              dtmp_c[m + l * stride_l_d + k * stride_k_d + j * stride_j_d + i * stride_i_d + nw * stride_nw_d] = 0;
              for(int n=0; n<elec_num; n++){
                dtmp_c[m + l * stride_l_d + k * stride_k_d + j * stride_j_d + i * stride_i_d + nw * stride_nw_d] =
                dtmp_c[m + l * stride_l_d + k * stride_k_d + j * stride_j_d + i * stride_i_d + nw * stride_nw_d] +
                een_rescaled_e_deriv_e[m + l * stride_l_e +  n * stride_n_e + i * stride_i_e + nw * stride_nw_e] *
                een_rescaled_n[n + k * stride_k_n + j * stride_j_n + nw * stride_nw_n];
              }
            }
          }
        }
      }
    }
  }
  }

  return QMCKL_SUCCESS;
}
#endif
     #+end_src

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
#ifdef HAVE_OPENMP_OFFLOAD
    qmckl_exit_code qmckl_compute_dtmp_c_omp_offload (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c );
#endif
     #+end_src

**** cuBLAS offload                                                :noexport:

     #+begin_src c :comments org :tangle (eval c) :noweb yes
#ifdef HAVE_CUBLAS_OFFLOAD
qmckl_exit_code
qmckl_compute_dtmp_c_cublas_offload (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c ) {

  if (context == QMCKL_NULL_CONTEXT) {
    return QMCKL_INVALID_CONTEXT;
  }

  if (cord_num < 0) {
    return QMCKL_INVALID_ARG_2;
  }

  if (elec_num <= 0) {
    return QMCKL_INVALID_ARG_3;
  }

  if (nucl_num <= 0) {
    return QMCKL_INVALID_ARG_4;
  }

  if (walk_num <= 0) {
    return QMCKL_INVALID_ARG_5;
  }

  qmckl_exit_code  info = QMCKL_SUCCESS;

  //cuBLAS initialization
  cublasHandle_t handle;
  if (cublasCreate(&handle) != CUBLAS_STATUS_SUCCESS)
  {
    fprintf(stdout, "CUBLAS initialization failed!\n");
    exit(EXIT_FAILURE);
  }

  const double alpha = 1.0;
  const double beta  = 0.0;

  const int64_t M = 4*elec_num;
  const int64_t N = nucl_num*(cord_num + 1);
  const int64_t K = elec_num;

  const int64_t LDA = 4*elec_num;
  const int64_t LDB = elec_num;
  const int64_t LDC = 4*elec_num;

  const int64_t af = elec_num*elec_num*4;
  const int64_t bf = elec_num*nucl_num*(cord_num+1);
  const int64_t cf = elec_num*4*nucl_num*(cord_num+1);

  #pragma omp target enter data map(to:een_rescaled_e_deriv_e[0:elec_num*4*elec_num*(cord_num+1)*walk_num], een_rescaled_n[0:elec_num*nucl_num*(cord_num+1)*walk_num], dtmp_c[0:elec_num*4*nucl_num*(cord_num+1)*cord_num*walk_num])
  #pragma omp target data use_device_ptr(een_rescaled_e_deriv_e, een_rescaled_n, dtmp_c)
  {
  for (int64_t nw=0; nw < walk_num; ++nw) {
    int cublasError = cublasDgemmStridedBatched(handle, CUBLAS_OP_N, CUBLAS_OP_N, M, N, K, &alpha,
                                      &(een_rescaled_e_deriv_e[(nw*(cord_num+1))]),
                                      LDA, af,
                                      &(een_rescaled_n[bf*nw]), LDB, 0,
                                      &beta,
                                      &(dtmp_c[(nw*cord_num)]),
                                      LDC, cf, cord_num);

  }
  }

  #pragma omp target exit data map(from:dtmp_c[0:cf*cord_num*walk_num])

  cublasDestroy(handle);
  return info;
}
#endif
     #+end_src

     #+RESULTS:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
#ifdef HAVE_CUBLAS_OFFLOAD
    qmckl_exit_code qmckl_compute_dtmp_c_cublas_offload (
      const qmckl_context context,
      const int64_t cord_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t walk_num,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n,
      double* const dtmp_c );
#endif
     #+end_src

*** Test

    #+name: helper_funcs
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

elec_coord = np.array(elec_coord)[0]
nucl_coord = np.array(nucl_coord)
elnuc_dist = np.zeros(shape=(elec_num, nucl_num),dtype=float)
for i in range(elec_num):
  for a in range(nucl_num):
    elnuc_dist[i, a] = np.linalg.norm(elec_coord[i] - nucl_coord[:,a])

kappa = 1.0

een_rescaled_n = np.zeros(shape=(nucl_num, elec_num, cord_num + 1), dtype=float)
een_rescaled_n[:,:,0] = 1.0

for a in range(nucl_num):
  for i in range(elec_num):
    een_rescaled_n[a, i, 1] = np.exp(-kappa * elnuc_dist[i, a])

for l in range(2,cord_num+1):
  for a in range(nucl_num):
    for i in range(elec_num):
      een_rescaled_n[a, i, l] = een_rescaled_n[a, i, l - 1] * een_rescaled_n[a, i, 1]

elec_dist = np.zeros(shape=(elec_num, elec_num),dtype=float)
for i in range(elec_num):
  for j in range(elec_num):
    elec_dist[i, j] = np.linalg.norm(elec_coord[i] - elec_coord[j])

kappa = 1.0

een_rescaled_e_ij = np.zeros(shape=(elec_num * (elec_num - 1)//2, cord_num+1), dtype=float)
een_rescaled_e_ij[:,0] = 1.0

k = 0
for j in range(elec_num):
  for i in range(j):
    een_rescaled_e_ij[k, 1] = np.exp(-kappa * elec_dist[i, j])
    k = k + 1

for l in range(2, cord_num + 1):
  for k in range(elec_num * (elec_num - 1)//2):
    een_rescaled_e_ij[k, l] = een_rescaled_e_ij[k, l - 1] * een_rescaled_e_ij[k, 1]

een_rescaled_e = np.zeros(shape=(elec_num, elec_num, cord_num + 1), dtype=float)
een_rescaled_e[:,:,0] = 1.0

for l in range(1,cord_num+1):
  k = 0
  for j in range(elec_num):
    for i in range(j):
      x = een_rescaled_e_ij[k, l]
      een_rescaled_e[i, j, l] = x
      een_rescaled_e[j, i, l] = x
      k = k + 1

for l in range(0,cord_num+1):
  for j in range(0, elec_num):
    een_rescaled_e[j,j,l] = 0.0

lkpm_of_cindex = np.array(lkpm_combined_index).T
    #+end_src

    #+RESULTS: helper_funcs

     #+begin_src c :tangle (eval c_test)
assert(qmckl_electron_provided(context));

double tmp_c[walk_num][cord_num][cord_num+1][nucl_num][elec_num];
rc = qmckl_get_jastrow_tmp_c(context, &(tmp_c[0][0][0][0][0]));

double dtmp_c[walk_num][cord_num][cord_num+1][nucl_num][4][elec_num];
rc = qmckl_get_jastrow_dtmp_c(context, &(dtmp_c[0][0][0][0][0][0]));

printf("%e\n%e\n", tmp_c[0][0][1][0][0], 2.7083473948352403);
assert(fabs(tmp_c[0][0][1][0][0] - 2.7083473948352403) < 1e-12);

printf("%e\n%e\n", dtmp_c[0][1][0][0][0][0],0.237440520852232);
assert(fabs(dtmp_c[0][1][0][0][0][0] - 0.237440520852232) < 1e-12);
     #+end_src

** Electron-electron-nucleus Jastrow \(f_{een}\)

  Calculate the electron-electron-nuclear three-body jastrow component ~factor_een~
  using the above prepared tables.

  TODO: write equations.

*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_factor_een(qmckl_context context,
                             double* const factor_een,
                             const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_factor_een(qmckl_context context,
                             double* const factor_een,
                             const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_factor_een(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.walker.num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_een",
                           "Array too small. Expected walk_num");
  }
  memcpy(factor_een, ctx->jastrow.factor_een, sze*sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

**** Fortran interface

#+begin_src f90 :tangle (eval fh_func) :comments org
interface
   integer(qmckl_exit_code) function qmckl_get_jastrow_factor_een (context, &
        factor_een, size_max) bind(C)
     use, intrinsic :: iso_c_binding
     import
     implicit none
     integer (qmckl_context) , intent(in), value :: context
     integer(c_int64_t), intent(in), value       :: size_max
     double precision, intent(out)               :: factor_een(size_max)
   end function qmckl_get_jastrow_factor_een
end interface
#+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_factor_een(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_factor_een(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Check if en rescaled distance is provided */
  rc = qmckl_provide_een_rescaled_e(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_een_rescaled_n(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_jastrow_c_vector_full(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_lkpm_combined_index(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if tmp_c is provided */
  rc = qmckl_provide_tmp_c(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.factor_een_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.factor_een != NULL) {
        rc = qmckl_free(context, ctx->jastrow.factor_een);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_factor_een",
                                 "Unable to free ctx->jastrow.factor_een");
        }
        ctx->jastrow.factor_een = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.factor_een == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walker.num * sizeof(double);
      double* factor_een = (double*) qmckl_malloc(context, mem_info);

      if (factor_een == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_factor_een",
                               NULL);
      }
      ctx->jastrow.factor_een = factor_een;
    }

    rc = qmckl_compute_factor_een(context,
                                  ctx->electron.walker.num,
                                  ctx->electron.num,
                                  ctx->nucleus.num,
                                  ctx->jastrow.cord_num,
                                  ctx->jastrow.dim_c_vector,
                                  ctx->jastrow.c_vector_full,
                                  ctx->jastrow.lkpm_combined_index,
                                  ctx->jastrow.tmp_c,
                                  ctx->jastrow.een_rescaled_n,
                                  ctx->jastrow.factor_een);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.factor_een_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute naive
   :PROPERTIES:
   :Name:     qmckl_compute_factor_een_naive
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_een_naive_args
    | Variable              | Type                                               | In/Out | Description                          |
    |-----------------------+----------------------------------------------------+--------+--------------------------------------|
    | ~context~             | ~qmckl_context~                                    | in     | Global state                         |
    | ~walk_num~            | ~int64_t~                                          | in     | Number of walkers                    |
    | ~elec_num~            | ~int64_t~                                          | in     | Number of electrons                  |
    | ~nucl_num~            | ~int64_t~                                          | in     | Number of nucleii                    |
    | ~cord_num~            | ~int64_t~                                          | in     | order of polynomials                 |
    | ~dim_c_vector~       | ~int64_t~                                          | in     | dimension of full coefficient vector |
    | ~c_vector_full~      | ~double[dim_c_vector][nucl_num]~                  | in     | full coefficient vector              |
    | ~lkpm_combined_index~ | ~int64_t[4][dim_c_vector]~                        | in     | combined indices                     |
    | ~een_rescaled_e~      | ~double[walk_num][elec_num][elec_num][0:cord_num]~ | in     | Electron-nucleus rescaled            |
    | ~een_rescaled_n~      | ~double[walk_num][elec_num][nucl_num][0:cord_num]~ | in     | Electron-nucleus rescaled factor     |
    | ~factor_een~          | ~double[walk_num]~                                 | out    | Electron-nucleus jastrow             |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_een_naive_f( &
     context, walk_num, elec_num, nucl_num, cord_num,&
     dim_c_vector, c_vector_full, lkpm_combined_index, &
     een_rescaled_e, een_rescaled_n, factor_een) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, cord_num, nucl_num, dim_c_vector
  integer*8             , intent(in)  :: lkpm_combined_index(dim_c_vector,4)
  double precision      , intent(in)  :: c_vector_full(nucl_num, dim_c_vector)
  double precision      , intent(in)  :: een_rescaled_e(0:cord_num, elec_num, elec_num, walk_num)
  double precision      , intent(in)  :: een_rescaled_n(0:cord_num, nucl_num, elec_num, walk_num)
  double precision      , intent(out) :: factor_een(walk_num)

  integer*8 :: i, a, j, l, k, p, m, n, nw
  double precision :: accu, accu2, cn

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  factor_een = 0.0d0

  do nw =1, walk_num
  do n = 1, dim_c_vector
    l = lkpm_combined_index(n, 1)
    k = lkpm_combined_index(n, 2)
    p = lkpm_combined_index(n, 3)
    m = lkpm_combined_index(n, 4)

    do a = 1, nucl_num
      accu2 = 0.0d0
      cn = c_vector_full(a, n)
      do j = 1, elec_num
        accu = 0.0d0
        do i = 1, elec_num
          accu = accu + een_rescaled_e(k,i,j,nw) *       &
                        een_rescaled_n(m,a,i,nw)
          !if(nw .eq. 1) then
          !  print *,l,k,p,m,j,i,een_rescaled_e(k,i,j,nw), een_rescaled_n(m,a,i,nw), accu
          !endif
        end do
        accu2 = accu2 + accu * een_rescaled_n(m + l,a,j,nw)
        !print *, l,m,nw,accu, accu2, een_rescaled_n(m + l, a, j, nw), cn, factor_een(nw)
      end do
      factor_een(nw) = factor_een(nw) + accu2 * cn
    end do
  end do
  end do

end function qmckl_compute_factor_een_naive_f
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_een_naive_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_een_naive (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t cord_num,
      const int64_t dim_c_vector,
      const double* c_vector_full,
      const int64_t* lkpm_combined_index,
      const double* een_rescaled_e,
      const double* een_rescaled_n,
      double* const factor_een );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_factor_een_naive_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_factor_een_naive &
    (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         een_rescaled_e, &
         een_rescaled_n, &
         factor_een) &
    bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: cord_num
      integer (c_int64_t) , intent(in)  , value :: dim_c_vector
      real    (c_double ) , intent(in)          :: c_vector_full(nucl_num,dim_c_vector)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_c_vector,4)
      real    (c_double ) , intent(in)          :: een_rescaled_e(0:cord_num,elec_num,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_n(0:cord_num,nucl_num,elec_num,walk_num)
      real    (c_double ) , intent(out)         :: factor_een(walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_een_naive_f
      info = qmckl_compute_factor_een_naive_f &
         (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         een_rescaled_e, &
         een_rescaled_n, &
         factor_een)

    end function qmckl_compute_factor_een_naive
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_een
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_een_args
    | Variable              | Type                                                             | In/Out                          | Description                          |
    |-----------------------+------------------------------------------------------------------+---------------------------------+--------------------------------------|
    | ~context~             | ~qmckl_context~                                                  | in                              | Global state                         |
    | ~walk_num~            | ~int64_t~                                                        | in                              | Number of walkers                    |
    | ~elec_num~            | ~int64_t~                                                        | in                              | Number of electrons                  |
    | ~nucl_num~            | ~int64_t~                                                        | in                              | Number of nucleii                    |
    | ~cord_num~            | ~int64_t~                                                        | in                              | order of polynomials                 |
    | ~dim_c_vector~       | ~int64_t~                                                        | in                              | dimension of full coefficient vector |
    | ~c_vector_full~      | ~double[dim_c_vector][nucl_num]~                                | in                              | full coefficient vector              |
    | ~lkpm_combined_index~ | ~int64_t[4][dim_c_vector]~                                      | in                              | combined indices                     |
    | ~tmp_c~               | ~double[walk_num][0:cord_num-1][0:cord_num][nucl_num][elec_num]~ | vector of non-zero coefficients |                                      |
    | ~een_rescaled_n~      | ~double[walk_num][0:cord_num][nucl_num][elec_num]~               | in                              | Electron-nucleus rescaled factor     |
    | ~factor_een~          | ~double[walk_num]~                                               | out                             | Electron-nucleus jastrow             |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_een_f( &
     context, walk_num, elec_num, nucl_num, cord_num,   &
     dim_c_vector, c_vector_full, lkpm_combined_index, &
     tmp_c, een_rescaled_n, factor_een) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, cord_num, nucl_num, dim_c_vector
  integer*8             , intent(in)  :: lkpm_combined_index(dim_c_vector,4)
  double precision      , intent(in)  :: c_vector_full(nucl_num, dim_c_vector)
  double precision      , intent(in)  :: tmp_c(elec_num, nucl_num,0:cord_num, 0:cord_num-1,  walk_num)
  double precision      , intent(in)  :: een_rescaled_n(elec_num, nucl_num, 0:cord_num, walk_num)
  double precision      , intent(out) :: factor_een(walk_num)

  integer*8 :: i, a, j, l, k, p, m, n, nw
  double precision :: accu, accu2, cn

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  factor_een = 0.0d0

  do nw =1, walk_num
  do n = 1, dim_c_vector
    l = lkpm_combined_index(n, 1)
    k = lkpm_combined_index(n, 2)
    p = lkpm_combined_index(n, 3)
    m = lkpm_combined_index(n, 4)

    do a = 1, nucl_num
      cn = c_vector_full(a, n)
      if(cn == 0.d0) cycle

      accu = 0.0d0
      do j = 1, elec_num
        accu = accu + een_rescaled_n(j,a,m,nw) * tmp_c(j,a,m+l,k,nw)
      end do
      factor_een(nw) = factor_een(nw) + accu * cn
    end do
  end do
  end do

end function qmckl_compute_factor_een_f
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_een_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_een (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t cord_num,
      const int64_t dim_c_vector,
      const double* c_vector_full,
      const int64_t* lkpm_combined_index,
      const double* een_rescaled_e,
      const double* een_rescaled_n,
      double* const factor_een );
    #+end_src

    #+CALL: generate_c_interface(table=qmckl_factor_een_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_factor_een &
    (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         een_rescaled_e, &
         een_rescaled_n, &
         factor_een) &
    bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: cord_num
      integer (c_int64_t) , intent(in)  , value :: dim_c_vector
      real    (c_double ) , intent(in)          :: c_vector_full(nucl_num,dim_c_vector)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_c_vector,4)
      real    (c_double ) , intent(in)          :: een_rescaled_e(0:cord_num,elec_num,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)
      real    (c_double ) , intent(out)         :: factor_een(walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_een_f
      info = qmckl_compute_factor_een_f &
         (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         een_rescaled_e, &
         een_rescaled_n, &
         factor_een)

    end function qmckl_compute_factor_een
    #+end_src

*** Test
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

<<helper_funcs>>

kappa = 1.0

factor_een = 0.0

for n in range(0, dim_c_vector):
  l = lkpm_of_cindex[0,n]
  k = lkpm_of_cindex[1,n]
  p = lkpm_of_cindex[2,n]
  m = lkpm_of_cindex[3,n]

  for a in range(0, nucl_num):
    accu2 = 0.0
    cn = c_vector_full[a][n]
    for j in range(0, elec_num):
      accu = 0.0
      for i in range(0, elec_num):
        accu = accu + een_rescaled_e[i,j,k] *       \
                      een_rescaled_n[a,i,m]
      accu2 = accu2 + accu * een_rescaled_n[a,j,m+l]
    factor_een = factor_een + accu2 * cn

print("factor_een:",factor_een)
    #+end_src

    #+RESULTS:
    : factor_een: -0.37407972141304213


     #+begin_src c :tangle (eval c_test)
/* Check if Jastrow is properly initialized */
assert(qmckl_jastrow_provided(context));

double factor_een[walk_num];
rc = qmckl_get_jastrow_factor_een(context, &(factor_een[0]),walk_num);

assert(fabs(factor_een[0] + 0.37407972141304213) < 1e-12);
     #+end_src

** Electron-electron-nucleus Jastrow \(f_{een}\) derivative

  Calculate the electron-electron-nuclear three-body jastrow component ~factor_een_deriv_e~
  using the above prepared tables.

  TODO: write equations.

*** Get
    #+begin_src c :comments org :tangle (eval h_func) :noweb yes
qmckl_exit_code
qmckl_get_jastrow_factor_een_deriv_e(qmckl_context context,
                                     double* const factor_een_deriv_e,
                                     const int64_t size_max);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code
qmckl_get_jastrow_factor_een_deriv_e(qmckl_context context,
                                     double* const factor_een_deriv_e,
                                     const int64_t size_max)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

  rc = qmckl_provide_factor_een_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.walker.num * 4 * ctx->electron.num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_een_deriv_e",
                           "Array too small. Expected 4*walk_num*elec_num");
  }
  memcpy(factor_een_deriv_e, ctx->jastrow.factor_een_deriv_e, sze*sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

*** Provide                                                        :noexport:
    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
qmckl_exit_code qmckl_provide_factor_een_deriv_e(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_factor_een_deriv_e(qmckl_context context)
{

  qmckl_exit_code rc;

  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_context_struct* const ctx = (qmckl_context_struct*) context;
  assert (ctx != NULL);

  /* Check if en rescaled distance is provided */
  rc = qmckl_provide_een_rescaled_e(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_een_rescaled_n(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance is provided */
  rc = qmckl_provide_een_rescaled_e_deriv_e(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_een_rescaled_n_deriv_e(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_jastrow_c_vector_full(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if en rescaled distance derivatives is provided */
  rc = qmckl_provide_lkpm_combined_index(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if tmp_c is provided */
  rc = qmckl_provide_tmp_c(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Check if dtmp_c is provided */
  rc = qmckl_provide_dtmp_c(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* Compute if necessary */
  if (ctx->date > ctx->jastrow.factor_een_deriv_e_date) {

    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
      if (ctx->jastrow.factor_een_deriv_e != NULL) {
        rc = qmckl_free(context, ctx->jastrow.factor_een_deriv_e);
        if (rc != QMCKL_SUCCESS) {
          return qmckl_failwith( context, rc,
                                 "qmckl_provide_factor_een_deriv_e",
                                 "Unable to free ctx->jastrow.factor_een_deriv_e");
        }
        ctx->jastrow.factor_een_deriv_e = NULL;
      }
    }

    /* Allocate array */
    if (ctx->jastrow.factor_een_deriv_e == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = 4 * ctx->electron.num * ctx->electron.walker.num * sizeof(double);
      double* factor_een_deriv_e = (double*) qmckl_malloc(context, mem_info);

      if (factor_een_deriv_e == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_provide_factor_een_deriv_e",
                               NULL);
      }
      ctx->jastrow.factor_een_deriv_e = factor_een_deriv_e;
    }

    rc = qmckl_compute_factor_een_deriv_e(context,
                                          ctx->electron.walker.num,
                                          ctx->electron.num,
                                          ctx->nucleus.num,
                                          ctx->jastrow.cord_num,
                                          ctx->jastrow.dim_c_vector,
                                          ctx->jastrow.c_vector_full,
                                          ctx->jastrow.lkpm_combined_index,
                                          ctx->jastrow.tmp_c,
                                          ctx->jastrow.dtmp_c,
                                          ctx->jastrow.een_rescaled_n,
                                          ctx->jastrow.een_rescaled_n_deriv_e,
                                          ctx->jastrow.factor_een_deriv_e);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.factor_een_deriv_e_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src

*** Compute Naive
   :PROPERTIES:
   :Name:     qmckl_compute_factor_een_deriv_e_naive
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_een_deriv_e_naive_args
    | Variable                 | Type                                                  | In/Out | Description                          |
    |--------------------------+-------------------------------------------------------+--------+--------------------------------------|
    | ~context~                | ~qmckl_context~                                       | in     | Global state                         |
    | ~walk_num~               | ~int64_t~                                             | in     | Number of walkers                    |
    | ~elec_num~               | ~int64_t~                                             | in     | Number of electrons                  |
    | ~nucl_num~               | ~int64_t~                                             | in     | Number of nucleii                    |
    | ~cord_num~               | ~int64_t~                                             | in     | order of polynomials                 |
    | ~dim_c_vector~          | ~int64_t~                                             | in     | dimension of full coefficient vector |
    | ~c_vector_full~         | ~double[dim_c_vector][nucl_num]~                     | in     | full coefficient vector              |
    | ~lkpm_combined_index~    | ~int64_t[4][dim_c_vector]~                           | in     | combined indices                     |
    | ~een_rescaled_e~         | ~double[walk_num][elec_num][elec_num][0:cord_num]~    | in     | Electron-nucleus rescaled            |
    | ~een_rescaled_n~         | ~double[walk_num][elec_num][nucl_num][0:cord_num]~    | in     | Electron-nucleus rescaled factor     |
    | ~een_rescaled_e_deriv_e~ | ~double[walk_num][elec_num][4][elec_num][0:cord_num]~ | in     | Electron-nucleus rescaled            |
    | ~een_rescaled_n_deriv_e~ | ~double[walk_num][elec_num][4][nucl_num][0:cord_num]~ | in     | Electron-nucleus rescaled factor     |
    | ~factor_een_deriv_e~     | ~double[walk_num][4][elec_num]~                       | out    | Electron-nucleus jastrow             |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_een_deriv_e_naive_f( &
     context, walk_num, elec_num, nucl_num, cord_num, dim_c_vector, &
     c_vector_full, lkpm_combined_index, een_rescaled_e, een_rescaled_n, &
     een_rescaled_e_deriv_e, een_rescaled_n_deriv_e, factor_een_deriv_e)&
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, cord_num, nucl_num, dim_c_vector
  integer*8             , intent(in)  :: lkpm_combined_index(dim_c_vector, 4)
  double precision      , intent(in)  :: c_vector_full(nucl_num, dim_c_vector)
  double precision      , intent(in)  :: een_rescaled_e(0:cord_num, elec_num, elec_num, walk_num)
  double precision      , intent(in)  :: een_rescaled_n(0:cord_num, nucl_num, elec_num, walk_num)
  double precision      , intent(in)  :: een_rescaled_e_deriv_e(0:cord_num, elec_num, 4, elec_num, walk_num)
  double precision      , intent(in)  :: een_rescaled_n_deriv_e(0:cord_num, nucl_num, 4, elec_num, walk_num)
  double precision      , intent(out) :: factor_een_deriv_e(elec_num, 4, walk_num)

  integer*8 :: i, a, j, l, k, p, m, n, nw
  double precision :: accu, accu2, cn
  double precision :: daccu(1:4), daccu2(1:4)

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  factor_een_deriv_e = 0.0d0

  do nw =1, walk_num
  do n = 1, dim_c_vector
    l = lkpm_combined_index(n, 1)
    k = lkpm_combined_index(n, 2)
    p = lkpm_combined_index(n, 3)
    m = lkpm_combined_index(n, 4)

    do a = 1, nucl_num
      cn = c_vector_full(a, n)
      do j = 1, elec_num
        accu = 0.0d0
        accu2 = 0.0d0
        daccu = 0.0d0
        daccu2 = 0.0d0
        do i = 1, elec_num
          accu = accu + een_rescaled_e(k, i, j, nw) *         &
                        een_rescaled_n(m, a, i, nw)
          accu2 = accu2 + een_rescaled_e(k, i, j, nw) *       &
                          een_rescaled_n(m + l, a, i, nw)
          daccu(1:4) = daccu(1:4) + een_rescaled_e_deriv_e(k, j, 1:4, i, nw) *         &
                                    een_rescaled_n(m, a, i, nw)
          daccu2(1:4) = daccu2(1:4) + een_rescaled_e_deriv_e(k, j, 1:4, i, nw) *       &
                                      een_rescaled_n(m + l, a, i, nw)
        end do
        factor_een_deriv_e(j, 1:4, nw) = factor_een_deriv_e(j, 1:4, nw) +              &
               (accu * een_rescaled_n_deriv_e(m + l, a, 1:4, j, nw)                    &
                + daccu(1:4) * een_rescaled_n(m + l, a, j, nw)                         &
                + daccu2(1:4) * een_rescaled_n(m, a, j, nw)                            &
                + accu2 * een_rescaled_n_deriv_e(m, a, 1:4, j, nw)) * cn

        factor_een_deriv_e(j, 4, nw) = factor_een_deriv_e(j, 4, nw) + 2.0d0 * (        &
            daccu (1) * een_rescaled_n_deriv_e(m + l, a, 1, j, nw) +                    &
            daccu (2) * een_rescaled_n_deriv_e(m + l, a, 2, j, nw) +                    &
            daccu (3) * een_rescaled_n_deriv_e(m + l, a, 3, j, nw) +                    &
            daccu2(1) * een_rescaled_n_deriv_e(m, a, 1, j, nw    ) +                    &
            daccu2(2) * een_rescaled_n_deriv_e(m, a, 2, j, nw    ) +                    &
            daccu2(3) * een_rescaled_n_deriv_e(m, a, 3, j, nw    ) ) * cn

      end do
    end do
  end do
  end do

end function qmckl_compute_factor_een_deriv_e_naive_f
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_een_deriv_e_naive_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_een_deriv_e_naive (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t cord_num,
      const int64_t dim_c_vector,
      const double* c_vector_full,
      const int64_t* lkpm_combined_index,
      const double* een_rescaled_e,
      const double* een_rescaled_n,
      const double* een_rescaled_e_deriv_e,
      const double* een_rescaled_n_deriv_e,
      double* const factor_een_deriv_e );
    #+end_src


    #+CALL: generate_c_interface(table=qmckl_factor_een_deriv_e_naive_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_factor_een_deriv_e_naive &
    (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         een_rescaled_e, &
         een_rescaled_n, &
         een_rescaled_e_deriv_e, &
         een_rescaled_n_deriv_e, &
         factor_een_deriv_e) &
    bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: cord_num
      integer (c_int64_t) , intent(in)  , value :: dim_c_vector
      real    (c_double ) , intent(in)          :: c_vector_full(nucl_num,dim_c_vector)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_c_vector,4)
      real    (c_double ) , intent(in)          :: een_rescaled_e(0:cord_num,elec_num,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_n(0:cord_num,nucl_num,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_e_deriv_e(0:cord_num,elec_num,4,elec_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_n_deriv_e(0:cord_num,nucl_num,4,elec_num,walk_num)
      real    (c_double ) , intent(out)         :: factor_een_deriv_e(elec_num,4,walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_een_deriv_e_naive_f
      info = qmckl_compute_factor_een_deriv_e_naive_f &
         (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         een_rescaled_e, &
         een_rescaled_n, &
         een_rescaled_e_deriv_e, &
         een_rescaled_n_deriv_e, &
         factor_een_deriv_e)

    end function qmckl_compute_factor_een_deriv_e_naive
    #+end_src

*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_factor_een_deriv_e
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_een_deriv_e_args
    | Variable                 | Type                                                                | In/Out | Description                                    |
    |--------------------------+---------------------------------------------------------------------+--------+------------------------------------------------|
    | ~context~                | ~qmckl_context~                                                     | in     | Global state                                   |
    | ~walk_num~               | ~int64_t~                                                           | in     | Number of walkers                              |
    | ~elec_num~               | ~int64_t~                                                           | in     | Number of electrons                            |
    | ~nucl_num~               | ~int64_t~                                                           | in     | Number of nucleii                              |
    | ~cord_num~               | ~int64_t~                                                           | in     | order of polynomials                           |
    | ~dim_c_vector~          | ~int64_t~                                                           | in     | dimension of full coefficient vector           |
    | ~c_vector_full~         | ~double[dim_c_vector][nucl_num]~                                   | in     | full coefficient vector                        |
    | ~lkpm_combined_index~    | ~int64_t[4][dim_c_vector]~                                         | in     | combined indices                               |
    | ~tmp_c~                  | ~double[walk_num][0:cord_num-1][0:cord_num][nucl_num][elec_num]~    | in     | Temporary intermediate tensor                  |
    | ~dtmp_c~                 | ~double[walk_num][0:cord_num-1][0:cord_num][nucl_num][4][elec_num]~ | in     | vector of non-zero coefficients                |
    | ~een_rescaled_n~         | ~double[walk_num][0:cord_num][nucl_num][elec_num]~                  | in     | Electron-nucleus rescaled factor               |
    | ~een_rescaled_n_deriv_e~ | ~double[walk_num][0:cord_num][nucl_num][4][elec_num]~               | in     | Derivative of Electron-nucleus rescaled factor |
    | ~factor_een_deriv_e~     | ~double[walk_num][4][elec_num]~                                     | out    | Derivative of Electron-nucleus jastrow         |


    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_factor_een_deriv_e_f( &
     context, walk_num, elec_num, nucl_num, &
     cord_num, dim_c_vector, c_vector_full, lkpm_combined_index, &
     tmp_c, dtmp_c, een_rescaled_n, een_rescaled_n_deriv_e, factor_een_deriv_e)&
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: walk_num, elec_num, cord_num, nucl_num, dim_c_vector
  integer*8             , intent(in)  :: lkpm_combined_index(dim_c_vector,4)
  double precision      , intent(in)  :: c_vector_full(nucl_num, dim_c_vector)
  double precision      , intent(in)  :: tmp_c(elec_num, nucl_num,0:cord_num, 0:cord_num-1,  walk_num)
  double precision      , intent(in)  :: dtmp_c(elec_num, 4, nucl_num,0:cord_num, 0:cord_num-1,  walk_num)
  double precision      , intent(in)  :: een_rescaled_n(elec_num, nucl_num, 0:cord_num, walk_num)
  double precision      , intent(in)  :: een_rescaled_n_deriv_e(elec_num, 4, nucl_num, 0:cord_num, walk_num)
  double precision      , intent(out) :: factor_een_deriv_e(elec_num,4,walk_num)

  integer*8 :: i, a, j, l, k, p, m, n, nw, ii
  double precision :: accu, accu2, cn

  info = QMCKL_SUCCESS

  if (context == QMCKL_NULL_CONTEXT) then
     info = QMCKL_INVALID_CONTEXT
     return
  endif

  if (walk_num <= 0) then
     info = QMCKL_INVALID_ARG_2
     return
  endif

  if (elec_num <= 0) then
     info = QMCKL_INVALID_ARG_3
     return
  endif

  if (nucl_num <= 0) then
     info = QMCKL_INVALID_ARG_4
     return
  endif

  if (cord_num < 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif

  factor_een_deriv_e = 0.0d0

  do nw =1, walk_num
  do n = 1, dim_c_vector
    l = lkpm_combined_index(n, 1)
    k = lkpm_combined_index(n, 2)
    p = lkpm_combined_index(n, 3)
    m = lkpm_combined_index(n, 4)

    do a = 1, nucl_num
      cn = c_vector_full(a, n)
      if(cn == 0.d0) cycle

      do ii = 1, 4
        do j = 1, elec_num
          factor_een_deriv_e(j,ii,nw) = factor_een_deriv_e(j,ii,nw) +                           (&
                                        tmp_c(j,a,m,k,nw)       * een_rescaled_n_deriv_e(j,ii,a,m+l,nw) + &
                                        (dtmp_c(j,ii,a,m,k,nw))   * een_rescaled_n(j,a,m+l,nw)            + &
                                        (dtmp_c(j,ii,a,m+l,k,nw)) * een_rescaled_n(j,a,m  ,nw)              + &
                                        tmp_c(j,a,m+l,k,nw)     * een_rescaled_n_deriv_e(j,ii,a,m,nw)     &
                                        ) * cn
        end do
      end do

      cn = cn + cn
      do j = 1, elec_num
        factor_een_deriv_e(j,4,nw) = factor_een_deriv_e(j,4,nw) +                              (&
                                      (dtmp_c(j,1,a,m  ,k,nw)) * een_rescaled_n_deriv_e(j,1,a,m+l,nw)  + &
                                      (dtmp_c(j,2,a,m  ,k,nw)) * een_rescaled_n_deriv_e(j,2,a,m+l,nw)  + &
                                      (dtmp_c(j,3,a,m  ,k,nw)) * een_rescaled_n_deriv_e(j,3,a,m+l,nw)  + &
                                      (dtmp_c(j,1,a,m+l,k,nw)) * een_rescaled_n_deriv_e(j,1,a,m  ,nw)  + &
                                      (dtmp_c(j,2,a,m+l,k,nw)) * een_rescaled_n_deriv_e(j,2,a,m  ,nw)  + &
                                      (dtmp_c(j,3,a,m+l,k,nw)) * een_rescaled_n_deriv_e(j,3,a,m  ,nw)    &
                                      ) * cn
      end do
    end do
  end do
  end do

end function qmckl_compute_factor_een_deriv_e_f
    #+end_src

#   #+CALL: generate_c_header(table=qmckl_factor_een_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+begin_src c :comments org :tangle (eval h_private_func) :noweb yes :exports none
    qmckl_exit_code qmckl_compute_factor_een_deriv_e (
      const qmckl_context context,
      const int64_t walk_num,
      const int64_t elec_num,
      const int64_t nucl_num,
      const int64_t cord_num,
      const int64_t dim_c_vector,
      const double* c_vector_full,
      const int64_t* lkpm_combined_index,
      const double* tmp_c,
      const double* dtmp_c,
      const double* een_rescaled_n,
      const double* een_rescaled_n_deriv_e,
      double* const factor_een_deriv_e );
    #+end_src


    #+CALL: generate_c_interface(table=qmckl_factor_een_deriv_e_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_factor_een_deriv_e &
    (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         tmp_c, &
         dtmp_c, &
         een_rescaled_n, &
         een_rescaled_n_deriv_e, &
         factor_een_deriv_e) &
    bind(C) result(info)

      use, intrinsic :: iso_c_binding
      implicit none

      integer (c_int64_t) , intent(in)  , value :: context
      integer (c_int64_t) , intent(in)  , value :: walk_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      integer (c_int64_t) , intent(in)  , value :: nucl_num
      integer (c_int64_t) , intent(in)  , value :: cord_num
      integer (c_int64_t) , intent(in)  , value :: dim_c_vector
      real    (c_double ) , intent(in)          :: c_vector_full(nucl_num,dim_c_vector)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_c_vector,4)
      real    (c_double ) , intent(in)          :: tmp_c(elec_num,nucl_num,0:cord_num,0:cord_num-1,walk_num)
      real    (c_double ) , intent(in)          :: dtmp_c(elec_num,4,nucl_num,0:cord_num,0:cord_num-1,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_n(elec_num,nucl_num,0:cord_num,walk_num)
      real    (c_double ) , intent(in)          :: een_rescaled_n_deriv_e(elec_num,4,nucl_num,0:cord_num,walk_num)
      real    (c_double ) , intent(out)         :: factor_een_deriv_e(elec_num,4,walk_num)

      integer(c_int32_t), external :: qmckl_compute_factor_een_deriv_e_f
      info = qmckl_compute_factor_een_deriv_e_f &
         (context, &
         walk_num, &
         elec_num, &
         nucl_num, &
         cord_num, &
         dim_c_vector, &
         c_vector_full, &
         lkpm_combined_index, &
         tmp_c, &
         dtmp_c, &
         een_rescaled_n, &
         een_rescaled_n_deriv_e, &
         factor_een_deriv_e)

    end function qmckl_compute_factor_een_deriv_e
    #+end_src

*** Test
    #+begin_src python :results output :exports none :noweb yes
import numpy as np

<<jastrow_data>>

<<een_e_deriv_e>>

<<helper_funcs>>

kappa = 1.0

factor_een = 0.0

daccu = np.zeros(4, dtype=float)
daccu2 = np.zeros(4, dtype=float)
een_rescaled_e_deriv_e_t = een_rescaled_e_deriv_e.T
print(een_rescaled_e_deriv_e_t.shape)
for n in range(0, dim_c_vector):
  l = lkpm_of_cindex[0,n]
  k = lkpm_of_cindex[1,n]
  p = lkpm_of_cindex[2,n]
  m = lkpm_of_cindex[3,n]

  for a in range(0, nucl_num):
    cn = c_vector_full[a][n]
    for j in range(0, elec_num):
      accu = 0.0
      accu2 = 0.0
      daccu = 0.0
      daccu2 = 0.0
      for i in range(0, elec_num):
        accu = accu + een_rescaled_e[i,j,k] *       \
                      een_rescaled_n[a,i,m]
        accu2 = accu2 + een_rescaled_e[i,j,k] *       \
                      een_rescaled_n[a,i,m+l]
#       daccu[0:4] = daccu[0:4] + een_rescaled_e_deriv_e_t[k,j,0:4,i,k] *       \
#                     een_rescaled_n[a,i,m]
#       daccu[0:4] = daccu[0:4] + een_rescaled_e_deriv_e_t[k,j,0:4,i,k] *       \
#                     een_rescaled_n[a,i,m]
      accu2 = accu2 + accu * een_rescaled_n[a,j,m+l]
#   factor_een = factor_een + accu2 * cn

print("factor_een:",factor_een)

    #+end_src

    #+RESULTS:
    : (6, 10, 4, 10)
    : factor_een: 0.0


     #+begin_src c :tangle (eval c_test)
/* Check if Jastrow is properly initialized */
assert(qmckl_jastrow_provided(context));

double factor_een_deriv_e[4][walk_num][elec_num];
rc = qmckl_get_jastrow_factor_een_deriv_e(context, &(factor_een_deriv_e[0][0][0]),4*walk_num*elec_num);

assert(fabs(factor_een_deriv_e[0][0][0] + 0.0005481671107226865) < 1e-12);
     #+end_src


** TODO Jastrow VGL functions

* End of files                                                     :noexport:

  #+begin_src c :tangle (eval h_private_type)
#endif
  #+end_src

  #+begin_src c :tangle (eval h_private_func)
#endif
  #+end_src

*** Test
  #+begin_src c :tangle (eval c_test)
    rc = qmckl_context_destroy(context);
    assert (rc == QMCKL_SUCCESS);

    return 0;
}
  #+end_src


# -*- mode: org -*-
# vim: syntax=c



