#+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 us 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:

  \[
  J_{\text{eN}}(\mathbf{r},\mathbf{R}) = \sum_{i=1}^{N_\text{elec}} \sum_{\alpha=1}^{N_\text{nucl}}
  \frac{a_1\, f(R_{i\alpha})}{1+a_2\, f(R_{i\alpha})} +
  \sum_{p=2}^{N_\text{ord}^a} a_{p+1}\, [f(R_{i\alpha})]^p - J_{eN}^\infty
  \]

  $J_{\text{ee}}$ 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:

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

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

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

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

  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"
  #+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                             |
    | ~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 Nucleii types                                           |
    | ~type_nucl_vector~        | ~int64_t[nucl_num]~                   | in     | IDs of types of Nucleii                                           |
    | ~aord_vector~             | ~double[aord_num + 1][type_nucl_num]~ | in     | Order of a polynomial coefficients                                |
    | ~bord_vector~             | ~double[bord_num + 1]~                | in     | Order of b polynomial coefficients                                |
    | ~cord_vector~             | ~double[cord_num][type_nucl_num]~     | in     | Order of c polynomial coefficients                                |
    | ~factor_ee~               | ~double[walk_num]~                    | out    | Jastrow factor: electron-electron part                            |
    | ~factor_ee_date~          | ~uint64_t~                            | out    | Jastrow factor: electron-electron part                            |
    | ~factor_en~               | ~double[walk_num]~                    | out    | Jastrow factor: electron-nucleus  part                            |
    | ~factor_en_date~          | ~uint64_t~                            | out    | Jastrow factor: electron-nucleus  part                            |
    | ~factor_een~              | ~double[walk_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][walk_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][walk_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][walk_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                                          | Description                     |
    |----------------------------+---------------------------------------------------------------------+-------------------------------------------------+---------------------------------|
    | ~dim_cord_vect~            | ~int64_t~                                                           | Number of unique C coefficients                 |                                 |
    | ~dim_cord_vect_date~       | ~uint64_t~                                                          | Number of unique C coefficients                 |                                 |
    | ~asymp_jasb~               | ~double[2]~                                                         | Asymptotic component                            |                                 |
    | ~asymp_jasb_date~          | ~uint64_t~                                                          | Asymptotic component                            |                                 |
    | ~cord_vect_full~           | ~double[dim_cord_vect][nucl_num]~                                   | vector of non-zero coefficients                 |                                 |
    | ~cord_vect_full_date~      | ~uint64_t~                                                          | Keep track of changes here                      |                                 |
    | ~lkpm_combined_index~      | ~int64_t[4][dim_cord_vect]~                                         | 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[walk_num][0:cord_num-1][0:cord_num][nucl_num][elec_num]~    | out                                             | vector of non-zero coefficients |
    | ~dtmp_c~                   | ~double[walk_num][elec_num][4][nucl_num][0:cord_num][0:cord_num-1]~ | vector of non-zero coefficients                 |                                 |

    | ~een_rescaled_n~              | ~double[walk_num][elec_num][nucl_num][0:cord_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[walk_num][elec_num][4][elec_num][0:cord_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[walk_num][elec_num][4][nucl_num][0:cord_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 =    [[[-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 = [
[ 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]

type_nucl_num = 1
aord_num     = 5
bord_num     = 5
cord_num     = 5
dim_cord_vect= 23
type_nucl_vector = [ 1, 1]
aord_vector = [
[0.000000000000000E+000],
[0.000000000000000E+000],
[-0.380512000000000E+000],
[-0.157996000000000E+000],
[-3.155800000000000E-002],
[2.151200000000000E-002]]

bord_vector = [ 0.500000000000000E-000,  0.153660000000000E-000,  6.722620000000000E-002,
  2.157000000000000E-002,  7.309600000000000E-003,  2.866000000000000E-003]
cord_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 ]
cord_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_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;
  int64_t* type_nucl_vector;
  double * aord_vector;
  double * bord_vector;
  double * cord_vector;
  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_cord_vect;
  uint64_t  dim_cord_vect_date;
  double * cord_vect_full;
  uint64_t  cord_vect_full_date;
  int64_t* lkpm_combined_index;
  uint64_t  lkpm_combined_index_date;
  double * tmp_c;
  double * dtmp_c;
  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;
} 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* const) context;
  assert (ctx != NULL);

  ctx->jastrow.uninitialized = (1 << 5) - 1;

  /* Default values */

  return QMCKL_SUCCESS;
}
   #+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_aord_vector       (qmckl_context context, double * const aord_vector, const int64_t size_max);
qmckl_exit_code  qmckl_get_jastrow_bord_vector       (qmckl_context context, double * const bord_vector, const int64_t size_max);
qmckl_exit_code  qmckl_get_jastrow_cord_vector       (qmckl_context context, double * const cord_vector, 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* const) context;
  assert (ctx != NULL);

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

   #+NAME:post
   #+begin_src c :exports none
if ( (ctx->jastrow.uninitialized & mask) != 0) {
  return NULL;
}
   #+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* const) 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* const) context;
  assert (ctx != NULL);

  int32_t mask = 1 << 0;

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

  int32_t mask = 1 << 0;

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

  int32_t mask = 1 << 1;

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

  int32_t mask = 1 << 2;

  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_aord_vector (const qmckl_context context,
                               double * const aord_vector,
                               const int64_t size_max) {

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

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

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

  int32_t mask = 1 << 3;

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

  assert (ctx->jastrow.aord_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_aord_vector",
                           "Array too small. Expected (ctx->jastrow.aord_num + 1)*ctx->jastrow.type_nucl_num");
  }
  memcpy(aord_vector, ctx->jastrow.aord_vector, sze*sizeof(double));
  return QMCKL_SUCCESS;
}

qmckl_exit_code
qmckl_get_jastrow_bord_vector (const qmckl_context context,
                               double * const bord_vector,
                               const int64_t size_max) {

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

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

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

  int32_t mask = 1 << 4;

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

  assert (ctx->jastrow.bord_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_bord_vector",
                           "Array too small. Expected (ctx->jastrow.bord_num + 1)");
  }
  memcpy(bord_vector, ctx->jastrow.bord_vector, sze*sizeof(double));
  return QMCKL_SUCCESS;
}

qmckl_exit_code
qmckl_get_jastrow_cord_vector (const qmckl_context context,
                               double * const cord_vector,
                               const int64_t size_max) {

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

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

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

  int32_t mask = 1 << 5;

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

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

  int64_t dim_cord_vect;
  qmckl_exit_code rc = qmckl_get_jastrow_dim_cord_vect(context, &dim_cord_vect);
  if (rc != QMCKL_SUCCESS) return rc;

  int64_t sze=dim_cord_vect * ctx->jastrow.type_nucl_num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_cord_vector",
                           "Array too small. Expected dim_cord_vect * jastrow.type_nucl_num");
  }
  memcpy(cord_vector, ctx->jastrow.cord_vector, sze*sizeof(double));
  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_ord_num           (qmckl_context context, const int64_t aord_num, const int64_t bord_num, 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_aord_vector       (qmckl_context context, const double * aord_vector, const int64_t size_max);
qmckl_exit_code  qmckl_set_jastrow_bord_vector       (qmckl_context context, const double * bord_vector, const int64_t size_max);
qmckl_exit_code  qmckl_set_jastrow_cord_vector       (qmckl_context context, const double * cord_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* const) context;
   #+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_ord_num(qmckl_context context,
                          const int64_t aord_num,
                          const int64_t bord_num,
                          const int64_t cord_num)
{
<<pre2>>

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

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

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

  int32_t mask = 1 << 0;
  ctx->jastrow.aord_num = aord_num;
  ctx->jastrow.bord_num = bord_num;
  ctx->jastrow.cord_num = cord_num;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_type_nucl_num(qmckl_context context, const int64_t type_nucl_num)
{
<<pre2>>

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

  int32_t mask = 1 << 1;
  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)
{
<<pre2>>

  int32_t mask = 1 << 2;

  int64_t type_nucl_num;
  qmckl_exit_code rc = qmckl_get_jastrow_type_nucl_num(context, &type_nucl_num);
  if (rc != QMCKL_SUCCESS) return rc;

  if (type_nucl_num == 0) {
    return qmckl_failwith( context,
                           QMCKL_FAILURE,
                           "qmckl_set_jastrow_type_nucl_vector",
                           "type_nucl_num is not set");
  }

  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",
                             NULL);
    }
  }

  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_aord_vector(qmckl_context context,
                              double const * aord_vector,
                              const int64_t size_max)
{
<<pre2>>

  int32_t mask = 1 << 3;

  int64_t aord_num;
  qmckl_exit_code rc = qmckl_get_jastrow_aord_num(context, &aord_num);
  if (rc != QMCKL_SUCCESS) return rc;

  int64_t type_nucl_num;
  rc = qmckl_get_jastrow_type_nucl_num(context, &type_nucl_num);
  if (rc != QMCKL_SUCCESS) return rc;

  if (aord_num == 0) {
    return qmckl_failwith( context,
                           QMCKL_FAILURE,
                           "qmckl_set_jastrow_coefficient",
                           "aord_num is not set");
  }

  if (aord_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_aord_vector",
                           "aord_vector = NULL");
  }

  if (ctx->jastrow.aord_vector != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.aord_vector);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_ord_vector",
                             NULL);
    }
  }

  qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
  mem_info.size = (aord_num + 1) * 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_aord_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, aord_vector, mem_info.size);

  ctx->jastrow.aord_vector = new_array;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_bord_vector(qmckl_context context,
                              double const * bord_vector,
                              const int64_t size_max)
{
<<pre2>>

  int32_t mask = 1 << 4;

  int64_t bord_num;
  qmckl_exit_code rc = qmckl_get_jastrow_bord_num(context, &bord_num);
  if (rc != QMCKL_SUCCESS) return rc;

  if (bord_num == 0) {
    return qmckl_failwith( context,
                           QMCKL_FAILURE,
                           "qmckl_set_jastrow_coefficient",
                           "bord_num is not set");
  }

  if (bord_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_bord_vector",
                           "bord_vector = NULL");
  }

  if (ctx->jastrow.bord_vector != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.bord_vector);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_ord_vector",
                             NULL);
    }
  }

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

  if ((size_t) size_max < mem_info.size/sizeof(double)) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_set_jastrow_bord_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, bord_vector, mem_info.size);

  ctx->jastrow.bord_vector = new_array;

  <<post2>>
}


qmckl_exit_code
qmckl_set_jastrow_cord_vector(qmckl_context context,
                              double const * cord_vector,
                              const int64_t size_max)
{
<<pre2>>

  int32_t mask = 1 << 5;

  qmckl_exit_code rc = qmckl_provide_dim_cord_vect(context);
  if (rc != QMCKL_SUCCESS) return rc;

  int64_t dim_cord_vect;
  rc = qmckl_get_jastrow_dim_cord_vect(context, &dim_cord_vect);
  if (rc != QMCKL_SUCCESS) return rc;

  int64_t type_nucl_num;
  rc = qmckl_get_jastrow_type_nucl_num(context, &type_nucl_num);
  if (rc != QMCKL_SUCCESS) return rc;

  if (dim_cord_vect == 0) {
    return qmckl_failwith( context,
                           QMCKL_FAILURE,
                           "qmckl_set_jastrow_coefficient",
                           "dim_cord_vect is not set");
  }

  if (cord_vector == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_jastrow_cord_vector",
                           "cord_vector = NULL");
  }

  if (ctx->jastrow.cord_vector != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->jastrow.cord_vector);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_ord_vector",
                             NULL);
    }
  }

  qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
  mem_info.size = dim_cord_vect * 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_cord_vector",
                           "Array too small. Expected dim_cord_vect * 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, cord_vector, mem_info.size);

  ctx->jastrow.cord_vector = new_array;

  <<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* const) 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);
  }

  qmckl_exit_code rc = QMCKL_SUCCESS;
  return rc;


}
   #+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;
double  rescale_factor_kappa_ee   = 1.0;
double  rescale_factor_kappa_en   = 1.0;
double  nucl_rescale_factor_kappa = 1.0;
double* elec_coord    = &(n2_elec_coord[0][0][0]);

const double*   nucl_charge   = n2_charge;
int64_t  nucl_num      = n2_nucl_num;
double*  nucl_coord    = &(n2_nucl_coord[0][0]);
int64_t size_max;

/* Provide Electron data */

qmckl_exit_code rc;

assert(!qmckl_electron_provided(context));

int64_t n;
rc = qmckl_get_electron_num (context, &n);
assert(rc == QMCKL_NOT_PROVIDED);

rc = qmckl_get_electron_up_num (context, &n);
assert(rc == QMCKL_NOT_PROVIDED);

rc = qmckl_get_electron_down_num (context, &n);
assert(rc == QMCKL_NOT_PROVIDED);


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

rc = qmckl_get_electron_up_num (context, &n);
assert(rc == QMCKL_SUCCESS);
assert(n == elec_up_num);

rc = qmckl_get_electron_down_num (context, &n);
assert(rc == QMCKL_SUCCESS);
assert(n == elec_dn_num);

rc = qmckl_get_electron_num (context, &n);
assert(rc == QMCKL_SUCCESS);
assert(n == elec_num);

double k_ee = 0.;
double k_en = 0.;
rc = qmckl_get_electron_rescale_factor_ee (context, &k_ee);
assert(rc == QMCKL_SUCCESS);
assert(k_ee == 1.0);

rc = qmckl_get_electron_rescale_factor_en (context, &k_en);
assert(rc == QMCKL_SUCCESS);
assert(k_en == 1.0);

rc = qmckl_set_electron_rescale_factor_en(context, rescale_factor_kappa_en);
assert(rc == QMCKL_SUCCESS);

rc = qmckl_set_electron_rescale_factor_ee(context, rescale_factor_kappa_ee);
assert(rc == QMCKL_SUCCESS);

rc = qmckl_get_electron_rescale_factor_ee (context, &k_ee);
assert(rc == QMCKL_SUCCESS);
assert(k_ee == rescale_factor_kappa_ee);

rc = qmckl_get_electron_rescale_factor_en (context, &k_en);
assert(rc == QMCKL_SUCCESS);
assert(k_en == rescale_factor_kappa_en);


int64_t w;
rc = qmckl_get_electron_walk_num (context, &w);
assert(rc == QMCKL_NOT_PROVIDED);


rc = qmckl_set_electron_walk_num (context, walk_num);
assert(rc == QMCKL_SUCCESS);

rc = qmckl_get_electron_walk_num (context, &w);
assert(rc == QMCKL_SUCCESS);
assert(w == walk_num);

assert(qmckl_electron_provided(context));

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

double elec_coord2[walk_num*3*elec_num];

rc = 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_get_nucleus_num (context, &n);
assert(rc == QMCKL_NOT_PROVIDED);


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

rc = qmckl_get_nucleus_num (context, &n);
assert(rc == QMCKL_SUCCESS);
assert(n == nucl_num);

double k;
rc = qmckl_get_nucleus_rescale_factor (context, &k);
assert(rc == QMCKL_SUCCESS);
assert(k == 1.0);


rc = qmckl_set_nucleus_rescale_factor (context, nucl_rescale_factor_kappa);
assert(rc == QMCKL_SUCCESS);

rc = qmckl_get_nucleus_rescale_factor (context, &k);
assert(rc == QMCKL_SUCCESS);
assert(k == nucl_rescale_factor_kappa);

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

assert(!qmckl_nucleus_provided(context));

rc = 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_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_set_nucleus_charge(context, nucl_charge, nucl_num);
assert(rc == QMCKL_SUCCESS);

rc = 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 ~bord_vector~ and the electron-electron rescale factor ~rescale_factor_kappa~.

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

*** 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_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

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

  qmckl_context_struct* const ctx = (qmckl_context_struct* const) 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

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

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_asymp_jasb(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* const) context;
  assert (ctx != NULL);

  /* Check if ee kappa is provided */
  double rescale_factor_kappa_ee;
  rc = qmckl_get_electron_rescale_factor_ee(context, &rescale_factor_kappa_ee);
  if(rc != QMCKL_SUCCESS) return rc;

  /* 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;
    }

    qmckl_exit_code rc =
      qmckl_compute_asymp_jasb(context,
                                ctx->jastrow.bord_num,
                                ctx->jastrow.bord_vector,
                                rescale_factor_kappa_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_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 |
    | ~bord_vector~             | ~double[bord_num+1]~ | in     | Values of b             |
    | ~rescale_factor_kappa_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_asymp_jasb_f(context, bord_num, bord_vector, rescale_factor_kappa_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)  :: bord_vector(bord_num + 1)
  double precision      , intent(in)  :: rescale_factor_kappa_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_kappa_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 = bord_vector(1) * kappa_inv / (1.0d0 + bord_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) + bord_vector(p + 1) * x
     end do
  end do

end function qmckl_compute_asymp_jasb_f
    #+end_src

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

    double    kappa_inv, x, asym_one;

    kappa_inv = 1.0 / rescale_factor_kappa_ee;

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

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

    asym_one = bord_vector[0] * kappa_inv / (1.0 + bord_vector[1] * kappa_inv);
    asymp_jasb[0] = asym_one;
    asymp_jasb[1] = 0.5 * asym_one;

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

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    qmckl_exit_code qmckl_compute_asymp_jasb (
	  const qmckl_context context,
	  const int64_t bord_num,
	  const double* bord_vector,
	  const double rescale_factor_kappa_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 = bord_vector[0] * kappa_inv / (1.0 + bord_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] += bord_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* aord_vector = &(n2_aord_vector[0][0]);
double* bord_vector = &(n2_bord_vector[0]);
double* cord_vector = &(n2_cord_vector[0][0]);
int64_t dim_cord_vect=0;

/* Initialize the Jastrow data */
rc = qmckl_init_jastrow(context);
assert(!qmckl_jastrow_provided(context));

/* Set the data */
rc = qmckl_set_jastrow_ord_num(context, aord_num, bord_num, cord_num);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_jastrow_type_nucl_num(context, type_nucl_num);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_jastrow_type_nucl_vector(context, type_nucl_vector, nucl_num);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_jastrow_aord_vector(context, aord_vector,(aord_num+1)*type_nucl_num);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_jastrow_bord_vector(context, bord_vector,(bord_num+1));
assert(rc == QMCKL_SUCCESS);
rc = qmckl_get_jastrow_dim_cord_vect(context, &dim_cord_vect);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_jastrow_cord_vector(context, cord_vector,dim_cord_vect*type_nucl_num);
assert(rc == QMCKL_SUCCESS);

/* 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~.

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


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

  qmckl_exit_code rc;

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

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

  int64_t sze=ctx->electron.walk_num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_ee",
                           "Array too small. Expected walk_num");
  }
  memcpy(factor_ee, ctx->jastrow.factor_ee, 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_ee(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_factor_ee(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* const) context;
  assert (ctx != NULL);

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

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

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

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walk_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_factor_ee",
                               NULL);
      }
      ctx->jastrow.factor_ee = factor_ee;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_ee(context,
                              ctx->electron.walk_num,
                              ctx->electron.num,
                              ctx->electron.up_num,
                              ctx->jastrow.bord_num,
                              ctx->jastrow.bord_vector,
                              ctx->electron.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      |
    | ~bord_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,            &
                                           bord_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)  :: bord_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   :: pow_ser, x, spin_fact, 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 (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 + bord_vector(p + 1) * x
        end do

        if(j .LE. up_num .OR. i .GT. up_num) then
          spin_fact = 0.5d0
          ipar = 2
        endif

        factor_ee(nw) = factor_ee(nw) + spin_fact * bord_vector(1)  * &
                                ee_distance_rescaled(i,j,nw) / &
                                (1.0d0 + bord_vector(2) *   &
                                ee_distance_rescaled(i,j,nw))  &
                               -asymp_jasb(ipar) + power_ser

     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* bord_vector,
	  const double* ee_distance_rescaled,
	  const double* asymp_jasb,
	  double* const factor_ee ) {

  int ipar; // can we use a smaller integer?
  double pow_ser, 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 + bord_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 * bord_vector[0]  * \
                                x1 /  \
                                (1.0 + bord_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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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* bord_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 + bord_vector[p + 1] * x

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

    factor_ee = factor_ee + spin_fact * bord_vector[0] * ee_distance_rescaled[i][j] \
                          / (1.0 + bord_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_get_jastrow_factor_ee(context, factor_ee, walk_num);

// calculate factor_ee
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_factor_ee_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

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

  int64_t sze = ctx->electron.walk_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_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_factor_ee_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* const) context;
  assert (ctx != 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) {

    /* 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.walk_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_factor_ee_deriv_e",
                               NULL);
      }
      ctx->jastrow.factor_ee_deriv_e = factor_ee_deriv_e;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_ee_deriv_e(context,
                                      ctx->electron.walk_num,
                                      ctx->electron.num,
                                      ctx->electron.up_num,
                                      ctx->jastrow.bord_num,
                                      ctx->jastrow.bord_vector,
                                      ctx->electron.ee_distance_rescaled,
                                      ctx->electron.ee_distance_rescaled_deriv_e,
                                      ctx->jastrow.asymp_jasb,
                                      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      |
    | ~bord_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 |
    | ~asymp_jasb~                   | ~double[2]~                               | 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_f(context, walk_num, elec_num, up_num, bord_num,            &
                                           bord_vector, ee_distance_rescaled, ee_distance_rescaled_deriv_e,  &
					   asymp_jasb, 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)  :: bord_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)
  double precision      , intent(in)  :: asymp_jasb(2)
  double precision      , intent(out) :: factor_ee_deriv_e(elec_num,4,walk_num)

  integer*8 :: i, j, p, ipar, 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 + bord_vector(2) * x
        invden      = 1.0d0 / den
        invden2     = invden * invden
        invden3     = invden2 * invden
        xinv        = 1.0d0 / (x + 1.0d-18)
        ipar        = 1

        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 * bord_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 * bord_vector(2) * dx(ii) * dx(ii)

          factor_ee_deriv_e( j, ii, nw) = factor_ee_deriv_e( j, ii, nw) + spin_fact * bord_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 * bord_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_f
    #+end_src

    #+CALL: generate_c_header(table=qmckl_factor_ee_deriv_e_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_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* bord_vector,
	  const double* ee_distance_rescaled,
	  const double* ee_distance_rescaled_deriv_e,
	  const double* asymp_jasb,
	  double* const factor_ee_deriv_e );
    #+end_src


    #+CALL: generate_c_interface(table=qmckl_factor_ee_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_ee_deriv_e &
	(context, &
		 walk_num, &
		 elec_num, &
		 up_num, &
		 bord_num, &
		 bord_vector, &
		 ee_distance_rescaled, &
		 ee_distance_rescaled_deriv_e, &
		 asymp_jasb, &
		 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)          :: bord_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(in)          :: asymp_jasb(2)
      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_f
      info = qmckl_compute_factor_ee_deriv_e_f &
	     (context, &
		 walk_num, &
		 elec_num, &
		 up_num, &
		 bord_num, &
		 bord_vector, &
		 ee_distance_rescaled, &
		 ee_distance_rescaled_deriv_e, &
		 asymp_jasb, &
		 factor_ee_deriv_e)

    end function qmckl_compute_factor_ee_deriv_e
    #+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 + bord_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 * bord_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 * bord_vector[1] * dx[ii] * dx[ii]

        factor_ee_deriv_e[ii][j] = factor_ee_deriv_e[ii][j] + spin_fact * bord_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 * bord_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

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

  Calculate the electron-electron jastrow component ~factor_en~ using the ~aord_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_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

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

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

  int64_t sze=ctx->electron.walk_num;
  if (size_max < sze) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_jastrow_factor_en",
                           "Array too small. Expected walk_num");
  }
  memcpy(factor_en, ctx->jastrow.factor_en, 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_en(qmckl_context context);
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_factor_en(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* const) context;
  assert (ctx != NULL);

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

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

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

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walk_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_factor_en",
                               NULL);
      }
      ctx->jastrow.factor_en = factor_en;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_en(context,
                              ctx->electron.walk_num,
                              ctx->electron.num,
                              ctx->nucleus.num,
                              ctx->jastrow.type_nucl_num,
                              ctx->jastrow.type_nucl_vector,
                              ctx->jastrow.aord_num,
                              ctx->jastrow.aord_vector,
                              ctx->electron.en_distance_rescaled,
                              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     |
    | ~aord_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 |
    | ~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, aord_vector,                         &
                                           en_distance_rescaled, 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)  :: aord_vector(aord_num + 1, type_nucl_num)
  double precision      , intent(in)  :: en_distance_rescaled(elec_num, nucl_num, walk_num)
  double precision      , intent(out) :: factor_en(walk_num)

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

  factor_en = 0.0d0

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

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

        factor_en(nw) = factor_en(nw) + aord_vector(1, type_nucl_vector(a)) *  &
                                en_distance_rescaled(i, a, nw) /               &
                                (1.0d0 + aord_vector(2, type_nucl_vector(a)) * &
                                en_distance_rescaled(i, a, nw))                &
                                + power_ser

     end do
  end do
  end do

end function qmckl_compute_factor_en_f
    #+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* aord_vector,
	  const double* en_distance_rescaled,
	  double* const factor_en ) {


  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 (nucl_num <= 0) {
     return QMCKL_INVALID_ARG_4;
  }

  if (aord_num <= 0) {
     return QMCKL_INVALID_ARG_7;
  }


  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 = ee_distance_rescaled[j * (walk_num * elec_num) + i * (walk_num) + nw];
        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 + aord_vector[(p+1)-1 + (type_nucl_vector[a]-1) * aord_num] * x;
        }

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

      }
    }
  }

  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* aord_vector,
	  const double* en_distance_rescaled,
	  double* const factor_en );
    #+end_src


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

<<jastrow_data>>

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 + aord_vector[(p-1) + 1][type_nucl_vector[a]-1] * x

    factor_en = factor_en + aord_vector[0][type_nucl_vector[a]-1] * en_distance_rescaled[i][a] \
                          / (1.0 + aord_vector[1][type_nucl_vector[a]-1] * en_distance_rescaled[i][a])     \
                          + pow_ser
print("factor_en        :",factor_en)

    #+end_src

    #+RESULTS:
    : factor_en        : -5.865822569188727


     #+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(factor_en[0]+5.865822569188727) < 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_factor_en_deriv_e(context);
  if (rc != QMCKL_SUCCESS) return rc;

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

  int64_t sze = ctx->electron.walk_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*walk_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_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_factor_en_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* const) context;
  assert (ctx != 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) {

    /* 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.walk_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_factor_en_deriv_e",
                               NULL);
      }
      ctx->jastrow.factor_en_deriv_e = factor_en_deriv_e;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_en_deriv_e(context,
                              ctx->electron.walk_num,
                              ctx->electron.num,
                              ctx->nucleus.num,
                              ctx->jastrow.type_nucl_num,
                              ctx->jastrow.type_nucl_vector,
                              ctx->jastrow.aord_num,
                              ctx->jastrow.aord_vector,
                              ctx->electron.en_distance_rescaled,
                              ctx->electron.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                |
    | ~aord_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, aord_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)  :: aord_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, spin_fact, 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 + aord_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 * aord_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 * aord_vector(2, type_nucl_vector(a)) * dx(ii) * dx(ii)

          factor_en_deriv_e(i, ii, nw) = factor_en_deriv_e(i, ii, nw) + aord_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 * aord_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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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* aord_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, &
		 aord_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)          :: aord_vector(aord_num + 1, type_nucl_num)
      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, &
		 aord_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 + aord_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 * aord_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 * aord_vector[1][type_nucl_vector[a]-1] * dx[ii] * dx[ii]

        factor_en_deriv_e[ii][i] = factor_en_deriv_e[ii][i] + aord_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 * (aord_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 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* const) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * ctx->electron.num * ctx->electron.walk_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.walk_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* const) 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) {

    /* 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.walk_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_een_rescaled_e",
                               NULL);
      }
      ctx->jastrow.een_rescaled_e = een_rescaled_e;
    }

    qmckl_exit_code rc =
      qmckl_compute_een_rescaled_e(context,
                                ctx->electron.walk_num,
                                ctx->electron.num,
                                ctx->jastrow.cord_num,
                                ctx->electron.rescale_factor_kappa_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_kappa_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_f(context, walk_num, elec_num, cord_num, rescale_factor_kappa_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_kappa_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

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


  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             = 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_kappa_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_f
    #+end_src

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

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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_kappa_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=get_value("Name"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_een_rescaled_e &
	(context, walk_num, elec_num, cord_num, rescale_factor_kappa_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_kappa_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_f
      info = qmckl_compute_een_rescaled_e_f &
	     (context, walk_num, elec_num, cord_num, rescale_factor_kappa_ee, ee_distance, een_rescaled_e)

    end function qmckl_compute_een_rescaled_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]
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 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* const) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * 4 * ctx->electron.num * ctx->electron.walk_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.walk_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* const) 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) {

    /* 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.walk_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_een_rescaled_e_deriv_e",
                               NULL);
      }
      ctx->jastrow.een_rescaled_e_deriv_e = een_rescaled_e_deriv_e;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_een_rescaled_e_deriv_e(context,
                                ctx->electron.walk_num,
                                ctx->electron.num,
                                ctx->jastrow.cord_num,
                                ctx->electron.rescale_factor_kappa_ee,
                                ctx->electron.coord_new.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_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_kappa_ee~ | ~double~                                              | in     | Factor to rescale ee distances       |
    | ~coord_new~               | ~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_kappa_ee,  &
     coord_new, 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_kappa_ee
  double precision      , intent(in)  :: coord_new(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_new(i, ii, nw) - coord_new(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_kappa_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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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_kappa_ee,
	  const double* coord_new,
	  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_kappa_ee, &
		 coord_new, &
		 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_kappa_ee
      real    (c_double ) , intent(in)          :: coord_new(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_kappa_ee, &
		 coord_new, &
		 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)
//assert(qmckl_electron_provided(context));
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 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* const) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * ctx->nucleus.num * ctx->electron.walk_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.walk_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* const) 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) {

    /* 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.walk_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_een_rescaled_n",
                               NULL);
      }
      ctx->jastrow.een_rescaled_n = een_rescaled_n;
    }

    qmckl_exit_code rc =
      qmckl_compute_een_rescaled_n(context,
                                ctx->electron.walk_num,
                                ctx->electron.num,
                                ctx->nucleus.num,
                                ctx->jastrow.cord_num,
                                ctx->electron.rescale_factor_kappa_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                     |
    | ~cord_num~                | ~int64_t~                                          | in     | Order of polynomials                |
    | ~rescale_factor_kappa_en~ | ~double~                                           | 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, cord_num, rescale_factor_kappa_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)  :: cord_num
  double precision      , intent(in)  :: rescale_factor_kappa_en
  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_kappa_en * 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 cord_num,
	  const double rescale_factor_kappa_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] = 17.0;
  }

  for (int nw = 0; nw < walk_num; ++nw) {
    for (int a = 0; a < nucl_num; ++a) {
      for (int i = 0; i < elec_num; ++i) {
        // prepare the actual een table
        //een_rescaled_n(:, :, 0, nw) = 1.0d0
        een_rescaled_n[i + a * elec_num + 0 + nw * elec_num*nucl_num*(cord_num+1)] = 1.0;
        //een_rescaled_n(i, a, 1, nw) = dexp(-rescale_factor_kappa_en * en_distance(i, a, nw))
        een_rescaled_n[i + a*elec_num + elec_num*nucl_num + nw*elec_num*nucl_num*(cord_num+1)] = exp(-rescale_factor_kappa_en * \
                                                                              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_header(table=qmckl_factor_een_rescaled_n_args,rettyp=get_value("CRetType"),fname=get_value("Name"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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 cord_num,
	  const double rescale_factor_kappa_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* const) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.num * 4 * ctx->nucleus.num * ctx->electron.walk_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.walk_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* const) 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) {

    /* 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.walk_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_een_rescaled_n_deriv_e",
                               NULL);
      }
      ctx->jastrow.een_rescaled_n_deriv_e = een_rescaled_n_deriv_e;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_een_rescaled_n_deriv_e(context,
                                ctx->electron.walk_num,
                                ctx->electron.num,
                                ctx->nucleus.num,
                                ctx->jastrow.cord_num,
                                ctx->electron.rescale_factor_kappa_en,
                                ctx->electron.coord_new.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                     |
    | ~cord_num~                | ~int64_t~                                             | in     | Order of polynomials                |
    | ~rescale_factor_kappa_en~ | ~double~                                              | in     | Factor to rescale ee distances      |
    | ~coord_new~               | ~double[walk_num][3][elec_num]~                       | in     | Electron coordinates                |
    | ~coord~                   | ~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, &
     cord_num, rescale_factor_kappa_en,                                                               &
     coord_new, coord, 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)  :: cord_num
  double precision      , intent(in)  :: rescale_factor_kappa_en
  double precision      , intent(in)  :: coord_new(elec_num,3,walk_num)
  double precision      , intent(in)  :: coord(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_new(i, ii, nw) - coord(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
    kappa_l = - dble(l) * rescale_factor_kappa_en
    do a = 1, nucl_num
      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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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 cord_num,
	  const double rescale_factor_kappa_en,
	  const double* coord_new,
	  const double* coord,
	  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, &
		 cord_num, &
		 rescale_factor_kappa_en, &
		 coord_new, &
		 coord, &
		 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 :: cord_num
      real    (c_double ) , intent(in)  , value :: rescale_factor_kappa_en
      real    (c_double ) , intent(in)          :: coord_new(elec_num,3,walk_num)
      real    (c_double ) , intent(in)          :: coord(nucl_num,3)
      real    (c_double ) , intent(in)          :: en_distance(nucl_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)         :: 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, &
		 cord_num, &
		 rescale_factor_kappa_en, &
		 coord_new, &
		 coord, &
		 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 ~cord_vect_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_cord_vect(qmckl_context context, int64_t* const dim_cord_vect);
qmckl_exit_code qmckl_get_jastrow_cord_vect_full(qmckl_context context, double* const cord_vect_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_cord_vect(qmckl_context context, int64_t* const dim_cord_vect)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

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

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

  *dim_cord_vect = ctx->jastrow.dim_cord_vect;

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_get_jastrow_cord_vect_full(qmckl_context context, double* const cord_vect_full)
{
  if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return QMCKL_NULL_CONTEXT;
  }

  qmckl_exit_code rc;

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

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

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

  size_t sze = ctx->jastrow.dim_cord_vect * ctx->nucleus.num;
  memcpy(cord_vect_full, ctx->jastrow.cord_vect_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_dim_cord_vect(context);
  if (rc != QMCKL_SUCCESS) return rc;

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

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

  size_t sze = ctx->jastrow.dim_cord_vect * 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_dim_cord_vect(context);
  if (rc != QMCKL_SUCCESS) return rc;

  rc = qmckl_provide_cord_vect_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* const) context;
  assert (ctx != NULL);

  size_t sze = (ctx->jastrow.cord_num) * (ctx->jastrow.cord_num + 1)
               * ctx->electron.num * ctx->nucleus.num * ctx->electron.walk_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_dim_cord_vect(context);
  if (rc != QMCKL_SUCCESS) return rc;

  rc = qmckl_provide_cord_vect_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* const) 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.walk_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_dim_cord_vect(qmckl_context context);
qmckl_exit_code qmckl_provide_cord_vect_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_dim_cord_vect(qmckl_context context)
{

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

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

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

    qmckl_exit_code rc =
      qmckl_compute_dim_cord_vect(context,
                                  ctx->jastrow.cord_num,
                                  &(ctx->jastrow.dim_cord_vect));
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

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

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_provide_cord_vect_full(qmckl_context context)
{

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

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

  /* Check if dim_cord_vect is provided */
  qmckl_exit_code rc = qmckl_provide_dim_cord_vect(context);
  if(rc != QMCKL_SUCCESS) return rc;

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

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

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->jastrow.dim_cord_vect * ctx->nucleus.num * sizeof(double);
      double* cord_vect_full = (double*) qmckl_malloc(context, mem_info);

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

    qmckl_exit_code rc =
      qmckl_compute_cord_vect_full(context,
                                ctx->nucleus.num,
                                ctx->jastrow.dim_cord_vect,
                                ctx->jastrow.type_nucl_num,
                                ctx->jastrow.type_nucl_vector,
                                ctx->jastrow.cord_vector,
                                ctx->jastrow.cord_vect_full);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->jastrow.cord_vect_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* const) context;
  assert (ctx != NULL);

  /* Check if dim_cord_vect is provided */
  qmckl_exit_code rc = qmckl_provide_dim_cord_vect(context);
  if(rc != QMCKL_SUCCESS) return rc;

  /* 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_cord_vect * 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 =
      qmckl_compute_lkpm_combined_index(context,
                                ctx->jastrow.cord_num,
                                ctx->jastrow.dim_cord_vect,
                                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* const) context;
  assert (ctx != NULL);

  /* Check if dim_cord_vect is provided */
  qmckl_exit_code rc = qmckl_provide_dim_cord_vect(context);
  if(rc != QMCKL_SUCCESS) return rc;

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

    /* 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.walk_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;
    }

    qmckl_exit_code rc =
      qmckl_compute_tmp_c(context,
                          ctx->jastrow.cord_num,
                          ctx->electron.num,
                          ctx->nucleus.num,
                          ctx->electron.walk_num,
                          ctx->jastrow.een_rescaled_e,
                          ctx->jastrow.een_rescaled_n,
                          ctx->jastrow.tmp_c);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

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

  return QMCKL_SUCCESS;
}

qmckl_exit_code qmckl_provide_dtmp_c(qmckl_context context)
{

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

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

  /* Check if dim_cord_vect is provided */
  qmckl_exit_code rc = qmckl_provide_dim_cord_vect(context);
  if(rc != QMCKL_SUCCESS) return rc;

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

    /* 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.walk_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;
    }

    qmckl_exit_code rc =
      qmckl_compute_dtmp_c(context,
                          ctx->jastrow.cord_num,
                          ctx->electron.num,
                          ctx->nucleus.num,
                          ctx->electron.walk_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_cord_vect
   :PROPERTIES:
   :Name:     qmckl_compute_dim_cord_vect
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_dim_cord_vect_args
    | Variable        | Type            | In/Out | Description                       |
    |-----------------+-----------------+--------+-----------------------------------|
    | ~context~       | ~qmckl_context~ | in     | Global state                      |
    | ~cord_num~      | ~int64_t~       | in     | Order of polynomials              |
    | ~dim_cord_vect~ | ~int64_t~       | out    | dimension of cord_vect_full table |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_dim_cord_vect_f(context, cord_num, dim_cord_vect) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: cord_num
  integer*8             , intent(out) :: dim_cord_vect
  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_cord_vect = 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_cord_vect = dim_cord_vect + 1
      end do
    end do
  end do

end function qmckl_compute_dim_cord_vect_f
    #+end_src

    #+begin_src c :comments org :tangle (eval c) :noweb yes
qmckl_exit_code qmckl_compute_dim_cord_vect (
	  const qmckl_context context,
	  const int64_t cord_num,
	  int64_t* const dim_cord_vect){
  
  int         lmax;

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

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

  *dim_cord_vect = 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_cord_vect=*dim_cord_vect+1;
      }
    }
  }
  
  return QMCKL_SUCCESS;
}
    #+end_src

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

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    qmckl_exit_code qmckl_compute_dim_cord_vect (
	  const qmckl_context context,
	  const int64_t cord_num,
	  int64_t* const dim_cord_vect );
    #+end_src


*** Compute cord_vect_full
   :PROPERTIES:
   :Name:     qmckl_compute_cord_vect_full
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_factor_cord_vect_full_args
    | Variable           | Type                                   | In/Out | Description                  |
    |--------------------+----------------------------------------+--------+------------------------------|
    | ~context~          | ~qmckl_context~                        | in     | Global state                 |
    | ~nucl_num~         | ~int64_t~                              | in     | Number of atoms              |
    | ~dim_cord_vect~    | ~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 |
    | ~cord_vector~      | ~double[dim_cord_vect][type_nucl_num]~ | in     | dimension of cord full table |
    | ~cord_vect_full~   | ~double[dim_cord_vect][nucl_num]~      | out    | Full list of coefficients    |

    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_cord_vect_full_f(context, nucl_num, dim_cord_vect, type_nucl_num,  &
     type_nucl_vector, cord_vector, cord_vect_full) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: nucl_num
  integer*8             , intent(in)  :: dim_cord_vect
  integer*8             , intent(in)  :: type_nucl_num
  integer*8             , intent(in)  :: type_nucl_vector(nucl_num)
  double precision      , intent(in)  :: cord_vector(type_nucl_num, dim_cord_vect)
  double precision      , intent(out) :: cord_vect_full(nucl_num,dim_cord_vect)
  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_cord_vect <= 0) then
     info = QMCKL_INVALID_ARG_5
     return
  endif


  do a = 1, nucl_num
    cord_vect_full(a,1:dim_cord_vect) = cord_vector(type_nucl_vector(a),1:dim_cord_vect)
  end do

end function qmckl_compute_cord_vect_full_f
    #+end_src

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

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    qmckl_exit_code qmckl_compute_cord_vect_full (
	  const qmckl_context context,
	  const int64_t nucl_num,
	  const int64_t dim_cord_vect,
	  const int64_t type_nucl_num,
	  const int64_t* type_nucl_vector,
	  const double* cord_vector,
	  double* const cord_vect_full );
    #+end_src


    #+CALL: generate_c_interface(table=qmckl_factor_cord_vect_full_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_cord_vect_full &
	(context, nucl_num, dim_cord_vect, type_nucl_num, type_nucl_vector, cord_vector, cord_vect_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_cord_vect
      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)          :: cord_vector(type_nucl_num,dim_cord_vect)
      real    (c_double ) , intent(out)         :: cord_vect_full(nucl_num,dim_cord_vect)

      integer(c_int32_t), external :: qmckl_compute_cord_vect_full_f
      info = qmckl_compute_cord_vect_full_f &
	     (context, nucl_num, dim_cord_vect, type_nucl_num, type_nucl_vector, cord_vector, cord_vect_full)

    end function qmckl_compute_cord_vect_full
    #+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_cord_vect~       | ~int64_t~                   | in     | dimension of cord full table  |
    | ~lkpm_combined_index~ | ~int64_t[4][dim_cord_vect]~ | 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_cord_vect,  &
     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_cord_vect
  integer*8             , intent(out) :: lkpm_combined_index(dim_cord_vect, 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_cord_vect <= 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_cord_vect,
	  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_cord_vect <= 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_cord_vect] = k;
        lkpm_combined_index[kk + 2*dim_cord_vect] = p;
        lkpm_combined_index[kk + 3*dim_cord_vect] = 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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    qmckl_exit_code qmckl_compute_lkpm_combined_index (
	  const qmckl_context context,
	  const int64_t cord_num,
	  const int64_t dim_cord_vect,
	  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 f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_tmp_c_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_f
    #+end_src

    #+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 ) {

  qmckl_exit_code info;
  int          i, j, a, l, kk, p, lmax, nw;
  char         TransA, TransB;
  double       alpha, beta;
  int          M, N, K, LDA, LDB, LDC;

  TransA = 'N';
  TransB = 'N';
  alpha  = 1.0;
  beta   = 0.0;

  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;
  } 

  M = elec_num;
  N = nucl_num*(cord_num + 1);
  K = elec_num;
  
  LDA = sizeof(een_rescaled_e)/sizeof(double);
  LDB = sizeof(een_rescaled_n)/sizeof(double);
  LDC = sizeof(tmp_c)/sizeof(double);

  for (int nw=0; nw < walk_num; ++nw) {
    for (int i=0; i<cord_num; ++i){
    info = qmckl_dgemm(context,TransA, TransB, M, N, K, alpha,     \
                 //    &een_rescaled_e[0+0*elec_num+i*elec_num*elec_num+nw*elec_num*elec_num*(cord_num+1)], 
                       &een_rescaled_e[             i*elec_num*elec_num+nw*elec_num*elec_num*(cord_num+1)], \
                       LDA,                                        \
                 //    &een_rescaled_n[0+0*elec_num+0*elec_num*nucl_num+nw*elec_num*nucl_num*(cord_num+1)], 
                       &een_rescaled_n[                                 nw*elec_num*nucl_num*(cord_num+1)], \
                       LDB,                                        \
                       beta,                                       \
                 //    &tmp_c[0+0*elec_num+0*elec_num*nucl_num+i*elec_num*nucl_num*(cord_num+1)+nw*elec_num*nucl_num*(cord_num+1)*cord_num], 
                       &tmp_c[                                 i*elec_num*nucl_num*(cord_num+1)+nw*elec_num*nucl_num*(cord_num+1)*cord_num],        \
                       LDC);
    }
  }

  return info;
}
    #+end_src

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

    #+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

 TODO: FIX dtmp_c dimension in the table.
*** 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 f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_dtmp_c_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_f
    #+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 ) {

  qmckl_exit_code  info;
  char             TransA, TransB;
  double           alpha, beta;
  int              M, N, K, LDA, LDB, LDC;

  TransA = 'N';
  TransB = 'N';
  alpha = 1.0;
  beta  = 0.0;

  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;
  } 

  M = 4*elec_num;
  N = nucl_num*(cord_num + 1);
  K = elec_num;

  LDA = 4*sizeof(een_rescaled_e_deriv_e)/sizeof(double);
  LDB = sizeof(een_rescaled_n)/sizeof(double);
  LDC = 4*sizeof(dtmp_c)/sizeof(double);

  for (int nw=0; nw < walk_num; ++nw) {
    for (int i=0; nw < cord_num; ++i) {
      info = qmckl_dgemm(context,TransA, TransB, M, N, K, alpha,        \
              //&een_rescaled_e_deriv_e[0+0*elec_num+0*elec_num*4+i*elec_num*4*elec_num+nw*elec_num*4*elec_num*(cord_num+1)], 
                &een_rescaled_e_deriv_e[i*elec_num*4*elec_num+nw*elec_num*4*elec_num*(cord_num+1)],                \
                LDA,                                               \
              //&een_rescaled_n[0+0*elec_num+0*elec_num*nucl_num+nw*elec_num*nucl_num*(cord_num+1)],  
                &een_rescaled_n[nw*elec_num*nucl_num*(cord_num+1)],   \
                LDB,                                               \
                beta,                                              \
              //&dtmp_c[0+0*elec_num+0*elec_num*4+0*elec_num*4*nucl_num+i*elec_num*4*nucl_num*(cord_num+1)+nw*elec_num*4*nucl_num*(cord_num+1)*cord_num], 
                &dtmp_c[i*elec_num*4*nucl_num*(cord_num+1)+nw*elec_num*4*nucl_num*(cord_num+1)*cord_num], \
                LDC);
    }
  }

  return info;
}
    #+end_src

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

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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


*** 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]));

assert(fabs(tmp_c[0][0][1][0][0] - 2.7083473948352403) < 1e-12);

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

  int64_t sze = ctx->electron.walk_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

*** 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* const) 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_cord_vect_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) {

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

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = ctx->electron.walk_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;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_een(context,
                              ctx->electron.walk_num,
                              ctx->electron.num,
                              ctx->nucleus.num,
                              ctx->jastrow.cord_num,
                              ctx->jastrow.dim_cord_vect,
                              ctx->jastrow.cord_vect_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_cord_vect~       | ~int64_t~                                          | in     | dimension of full coefficient vector |
    | ~cord_vect_full~      | ~double[dim_cord_vect][nucl_num]~                  | in     | full coefficient vector              |
    | ~lkpm_combined_index~ | ~int64_t[4][dim_cord_vect]~                        | 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_cord_vect, cord_vect_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_cord_vect
  integer*8             , intent(in)  :: lkpm_combined_index(dim_cord_vect,4)
  double precision      , intent(in)  :: cord_vect_full(nucl_num, dim_cord_vect)
  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_cord_vect
    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 = cord_vect_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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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_cord_vect,
	  const double* cord_vect_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_cord_vect, &
		 cord_vect_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_cord_vect
      real    (c_double ) , intent(in)          :: cord_vect_full(nucl_num,dim_cord_vect)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_cord_vect,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_cord_vect, &
		 cord_vect_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_cord_vect~       | ~int64_t~                                                        | in                              | dimension of full coefficient vector |
    | ~cord_vect_full~      | ~double[dim_cord_vect][nucl_num]~                                | in                              | full coefficient vector              |
    | ~lkpm_combined_index~ | ~int64_t[4][dim_cord_vect]~                                      | 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_cord_vect, cord_vect_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_cord_vect
  integer*8             , intent(in)  :: lkpm_combined_index(dim_cord_vect,4)
  double precision      , intent(in)  :: cord_vect_full(nucl_num, dim_cord_vect)
  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_cord_vect
    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 = cord_vect_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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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_cord_vect,
	  const double* cord_vect_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_cord_vect, &
		 cord_vect_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_cord_vect
      real    (c_double ) , intent(in)          :: cord_vect_full(nucl_num,dim_cord_vect)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_cord_vect,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_cord_vect, &
		 cord_vect_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_cord_vect):
  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 = cord_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* const) context;
  assert (ctx != NULL);

  int64_t sze = ctx->electron.walk_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* const) 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_cord_vect_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) {

    /* 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.walk_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;
    }

    qmckl_exit_code rc =
      qmckl_compute_factor_een_deriv_e(context,
                              ctx->electron.walk_num,
                              ctx->electron.num,
                              ctx->nucleus.num,
                              ctx->jastrow.cord_num,
                              ctx->jastrow.dim_cord_vect,
                              ctx->jastrow.cord_vect_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_cord_vect~          | ~int64_t~                                             | in     | dimension of full coefficient vector |
    | ~cord_vect_full~         | ~double[dim_cord_vect][nucl_num]~                     | in     | full coefficient vector              |
    | ~lkpm_combined_index~    | ~int64_t[4][dim_cord_vect]~                           | 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_cord_vect, cord_vect_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_cord_vect
  integer*8             , intent(in)  :: lkpm_combined_index(dim_cord_vect, 4)
  double precision      , intent(in)  :: cord_vect_full(nucl_num, dim_cord_vect)
  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_cord_vect
    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 = cord_vect_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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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_cord_vect,
	  const double* cord_vect_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_cord_vect, &
		 cord_vect_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_cord_vect
      real    (c_double ) , intent(in)          :: cord_vect_full(nucl_num,dim_cord_vect)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_cord_vect,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_cord_vect, &
		 cord_vect_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_cord_vect~          | ~int64_t~                                                           | in     | dimension of full coefficient vector           |
    | ~cord_vect_full~         | ~double[dim_cord_vect][nucl_num]~                                   | in     | full coefficient vector                        |
    | ~lkpm_combined_index~    | ~int64_t[4][dim_cord_vect]~                                         | 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_cord_vect,            &
                                           cord_vect_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_cord_vect
  integer*8             , intent(in)  :: lkpm_combined_index(dim_cord_vect,4)
  double precision      , intent(in)  :: cord_vect_full(nucl_num, dim_cord_vect)
  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_cord_vect
    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 = cord_vect_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"))

    #+RESULTS:
    #+begin_src c :tangle (eval h_func) :comments org
    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_cord_vect,
	  const double* cord_vect_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_cord_vect, &
		 cord_vect_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_cord_vect
      real    (c_double ) , intent(in)          :: cord_vect_full(nucl_num,dim_cord_vect)
      integer (c_int64_t) , intent(in)          :: lkpm_combined_index(dim_cord_vect,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_cord_vect, &
		 cord_vect_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_cord_vect):
  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 = cord_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

* 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



