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

The molecular orbitals (MOs) are defined in the basis of AOs along with a AO to MO 
coefficient matrix \[C\]. Using these coefficients (e.g. from Hartree Fock SCF method)
the MOs are defined as follows:

\[
\phi_i(\mathbf{r}) = C_i * \chi_i (\mathbf{r})
\]


In this section we demonstrate how to use the QMCkl specific DGEMM
function to calculate the MOs.


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


  #+begin_src c :tangle (eval h_private_type)
#ifndef QMCKL_MO_HPT
#define QMCKL_MO_HPT

#include <stdbool.h>
  #+end_src

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

#include <stdio.h>
#include <math.h>
#include "chbrclf.h"
#include "qmckl_ao_private_func.h"
#include "qmckl_mo_private_func.h"

int main() {
    qmckl_context context;
    context = qmckl_context_create();

    qmckl_exit_code rc;
  #+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 "qmckl.h"
#include "qmckl_context_private_type.h"
#include "qmckl_memory_private_type.h"
#include "qmckl_memory_private_func.h"
#include "qmckl_ao_private_type.h"
#include "qmckl_ao_private_func.h"
#include "qmckl_mo_private_type.h"
#include "qmckl_mo_private_func.h"
  #+end_src

* Context

  The following arrays are stored in the context:

  |---------------+--------------------+----------------------|
  | ~mo_num~      |                    | Number of MOs        |
  | ~coefficient~ | ~[mo_num][ao_num]~ | Orbital coefficients |

  Computed data:
  
  |---------------+-------------------------+----------------------------------------------------------------------------------------|
  |---------------+-------------------------+----------------------------------------------------------------------------------------|
  | ~mo_vgl~      | ~[5][elec_num][mo_num]~ | Value, gradients, Laplacian of the MOs at electron positions                           |
  | ~mo_vgl_date~ | ~uint64_t~              | Late modification date of Value, gradients, Laplacian of the MOs at electron positions |
  |---------------+-------------------------+----------------------------------------------------------------------------------------|

** Data structure

   #+begin_src c :comments org :tangle (eval h_private_type)
typedef struct qmckl_mo_basis_struct {
  int64_t   mo_num;  
  double  * coefficient;

  double  * mo_vgl;
  int64_t   mo_vgl_date;

  int32_t   uninitialized;
  bool      provided;
} qmckl_mo_basis_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.

** Access functions

   #+begin_src c :comments org :tangle (eval h_func) :exports none
qmckl_exit_code
qmckl_get_mo_basis_mo_num (const qmckl_context context,
                           int64_t* mo_num);
   #+end_src

   #+begin_src c :comments org :tangle (eval c) :noweb yes :exports none
qmckl_exit_code
qmckl_get_mo_basis_mo_num (const qmckl_context context,
                           int64_t* mo_num)
{
   if (qmckl_context_check(context) == QMCKL_NULL_CONTEXT) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_CONTEXT,
                           "qmckl_get_mo_basis_mo_num",
                           NULL);
   return (int64_t) 0;
  }

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

  int32_t mask = 1;

  if ( (ctx->mo_basis.uninitialized & mask) != 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_get_mo_basis_mo_num",
                           NULL);
  }

  assert (ctx->mo_basis.mo_num > (int64_t) 0);
  ,*mo_num = ctx->mo_basis.mo_num;
  return QMCKL_SUCCESS;
}

   #+end_src

   #+begin_src c :comments org :tangle (eval h_func) :exports none
qmckl_exit_code
qmckl_get_mo_basis_coefficient (const qmckl_context context,
                                double* const coefficient,
                                const int64_t size_max);
   #+end_src

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

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

  int32_t mask = 1 << 1;

  if ( (ctx->ao_basis.uninitialized & mask) != 0) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_get_mo_basis_coefficient",
                           NULL);
  }

  if (coefficient == NULL) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_get_mo_basis_coefficient",
                           "NULL pointer");
  }

  if (size_max < ctx->ao_basis.ao_num * ctx->mo_basis.mo_num) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_3,
                           "qmckl_get_mo_basis_coefficient",
                           "Array too small. Expected mo_num * ao_num");
  }

  assert (ctx->mo_basis.coefficient != NULL);
  memcpy(coefficient, ctx->mo_basis.coefficient,
         ctx->ao_basis.ao_num * ctx->mo_basis.mo_num * sizeof(int64_t));

  return QMCKL_SUCCESS;
}
   #+end_src

   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_mo_basis_provided (const qmckl_context context);
   #+end_src

   #+begin_src c :comments org :tangle (eval c) :exports none
bool qmckl_mo_basis_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->mo_basis.provided;
}


   #+end_src

** Initialization functions

   To set the basis set, all the following functions need to be
   called.

   #+begin_src c :comments org :tangle (eval h_func)
qmckl_exit_code  qmckl_set_mo_basis_mo_num           (qmckl_context context, const int64_t   mo_num);
qmckl_exit_code  qmckl_set_mo_basis_coefficient      (qmckl_context context, const double  * coefficient);
   #+end_src

   #+NAME:pre
   #+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:post
   #+begin_src c  :exports none
ctx->mo_basis.uninitialized &= ~mask;
ctx->mo_basis.provided = (ctx->mo_basis.uninitialized == 0);
if (ctx->mo_basis.provided) {
  qmckl_exit_code rc_ = qmckl_finalize_basis(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_mo_basis_mo_num(qmckl_context context, const int64_t mo_num) {
  <<pre>>

  if (mo_num <= 0) {
    return qmckl_failwith( context,
                           QMCKL_INVALID_ARG_2,
                           "qmckl_set_mo_basis_mo_num",
                           "mo_num <= 0");
  }

  int32_t mask = 1 ;
  ctx->mo_basis.mo_num = mo_num;

  <<post>>
}

qmckl_exit_code  qmckl_set_mo_basis_coefficient(qmckl_context context, const double* coefficient) {
  <<pre>>

  int32_t mask = 1 << 1;

  if (ctx->mo_basis.coefficient != NULL) {
    qmckl_exit_code rc = qmckl_free(context, ctx->mo_basis.coefficient);
    if (rc != QMCKL_SUCCESS) {
      return qmckl_failwith( context, rc,
                             "qmckl_set_mo_basis_coefficient",
                             NULL);
    }
  }

  qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
  mem_info.size = ctx->ao_basis.ao_num * ctx->mo_basis.mo_num * sizeof(double);
  double* new_array = (double*) qmckl_malloc(context, mem_info);
  if (new_array == NULL) {
    return qmckl_failwith( context,
                           QMCKL_ALLOCATION_FAILED,
                           "qmckl_set_mo_basis_coefficient",
                           NULL);
  }

  memcpy(new_array, coefficient, mem_info.size);

  ctx->mo_basis.coefficient = new_array;

  <<post>>
}

   #+end_src

 When the basis set is completely entered, other data structures are
 computed to accelerate the calculations.

* Computation

** Computation of MOs

*** Get

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

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

  qmckl_exit_code rc;

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

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

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

  size_t sze = 5 * ctx->electron.num * ctx->mo_basis.mo_num;
  memcpy(mo_vgl, ctx->mo_basis.mo_vgl, sze * sizeof(double));

  return QMCKL_SUCCESS;
}
    #+end_src

    #+begin_src f90 :tangle (eval fh_func) :comments org :exports none
    interface
      integer(c_int32_t) function qmckl_get_mo_basis_vgl (context, mo_vgl) &
          bind(C)
        use, intrinsic :: iso_c_binding
        import
        implicit none

        integer (c_int64_t) , intent(in)  , value :: context
        double precision,     intent(out)         :: mo_vgl(*)
      end function
    end interface
    #+end_src

*** Provide

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

    #+begin_src c :comments org :tangle (eval c) :noweb yes  :exports none
qmckl_exit_code qmckl_provide_mo_vgl(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);

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

  if(!(ctx->electron.provided)) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_electron",
                           NULL);
  }
  
  if (!ctx->mo_basis.provided) {
    return qmckl_failwith( context,
                           QMCKL_NOT_PROVIDED,
                           "qmckl_mo_basis",
                           NULL);
  }

  /* Compute if necessary */
  if (ctx->electron.coord_new_date > ctx->mo_basis.mo_vgl_date) {

    /* Allocate array */
    if (ctx->mo_basis.mo_vgl == NULL) {

      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
      mem_info.size = 5 * ctx->electron.num * ctx->mo_basis.mo_num * sizeof(double);
      double* mo_vgl = (double*) qmckl_malloc(context, mem_info);

      if (mo_vgl == NULL) {
        return qmckl_failwith( context,
                               QMCKL_ALLOCATION_FAILED,
                               "qmckl_mo_basis_vgl",
                               NULL);
      }
      ctx->mo_basis.mo_vgl = mo_vgl;
    }

    qmckl_exit_code rc; 
    rc = qmckl_compute_mo_basis_vgl(context,
                                    ctx->ao_basis.ao_num,
                                    ctx->mo_basis.mo_num,
                                    ctx->electron.num,
                                    ctx->mo_basis.coefficient,
                                    ctx->ao_basis.ao_vgl,
                                    ctx->mo_basis.mo_vgl);
    if (rc != QMCKL_SUCCESS) {
      return rc;
    }

    ctx->mo_basis.mo_vgl_date = ctx->date;
  }

  return QMCKL_SUCCESS;
}
    #+end_src
    
*** Compute
   :PROPERTIES:
   :Name:     qmckl_compute_mo_basis_vgl
   :CRetType: qmckl_exit_code
   :FRetType: qmckl_exit_code
   :END:

    #+NAME: qmckl_mo_basis_gaussian_vgl_args
   | ~qmckl_context~ | ~context~                         | in  | Global state                              |
   | ~int64_t~       | ~ao_num~                          | in  | Number of AOs                             |
   | ~int64_t~       | ~mo_num~                          | in  | Number of MOs                             |
   | ~int64_t~       | ~elec_num~                        | in  | Number of electrons                       |
   | ~double~        | ~coef_normalized[mo_num][ao_num]~ | in  | AO to MO transformation matrix            |
   | ~double~        | ~ao_vgl[5][elec_num][ao_num]~     | in  | Value, gradients and Laplacian of the AOs |
   | ~double~        | ~mo_vgl[5][elec_num][mo_num]~     | out | Value, gradients and Laplacian of the MOs |
    
    #+begin_src f90 :comments org :tangle (eval f) :noweb yes
integer function qmckl_compute_mo_basis_vgl_f(context, &
     ao_num, mo_num, elec_num, &
     coef_normalized, ao_vgl, mo_vgl) &
     result(info)
  use qmckl
  implicit none
  integer(qmckl_context), intent(in)  :: context
  integer*8             , intent(in)  :: ao_num, mo_num
  integer*8             , intent(in)  :: elec_num
  double precision      , intent(in)  :: ao_vgl(ao_num,elec_num,5)
  double precision      , intent(in)  :: coef_normalized(ao_num,mo_num)
  double precision      , intent(out) :: mo_vgl(mo_num,elec_num,5)
  logical*8                     :: TransA, TransB
  double precision              :: alpha, beta
  integer                       :: info_qmckl_dgemm_value
  integer                       :: info_qmckl_dgemm_Gx   
  integer                       :: info_qmckl_dgemm_Gy   
  integer                       :: info_qmckl_dgemm_Gz   
  integer                       :: info_qmckl_dgemm_lap  
  integer*8                     :: M, N, K, LDA, LDB, LDC, i,j

  integer*8 :: inucl, iprim, iwalk, ielec, ishell
  double precision :: x, y, z, two_a, ar2, r2, v, cutoff
  TransA = .False.
  TransB = .False. 
  alpha = 1.0d0
  beta  = 0.0d0

  info = QMCKL_SUCCESS
  info_qmckl_dgemm_value = QMCKL_SUCCESS
  info_qmckl_dgemm_Gx    = QMCKL_SUCCESS
  info_qmckl_dgemm_Gy    = QMCKL_SUCCESS
  info_qmckl_dgemm_Gz    = QMCKL_SUCCESS
  info_qmckl_dgemm_lap   = QMCKL_SUCCESS
  
  ! Don't compute exponentials when the result will be almost zero.
  ! TODO : Use numerical precision here
  cutoff = -dlog(1.d-15)
  M = 1_8
  N = mo_num * 1_8
  K = ao_num * 1_8
  LDA = M
  LDB = K
  LDC = M

  do ielec = 1, elec_num
          ! Value
          info_qmckl_dgemm_value = qmckl_dgemm(context,TransA, TransB, M, N, K, alpha,     &
                                         ao_vgl(:, ielec, 1), LDA, &
                                         coef_normalized(1:ao_num,1:mo_num),size(coef_normalized,1) * 1_8,    &
                                         beta,                                       &
                                         mo_vgl(:,ielec,1),LDC)
          ! Grad_x
          info_qmckl_dgemm_Gx = qmckl_dgemm(context,TransA, TransB, M, N, K, alpha,     &
                                         ao_vgl(:, ielec, 2), LDA, &
                                         coef_normalized(1:ao_num,1:mo_num),size(coef_normalized,1) * 1_8,    &
                                         beta,                                       &
                                         mo_vgl(:,ielec,2),LDC)
          ! Grad_y
          info_qmckl_dgemm_Gy = qmckl_dgemm(context,TransA, TransB, M, N, K, alpha,     &
                                         ao_vgl(:, ielec,  3), LDA, &
                                         coef_normalized(1:ao_num,1:mo_num),size(coef_normalized,1) * 1_8,    &
                                         beta,                                       &
                                         mo_vgl(:,ielec,3),LDC)
          ! Grad_z
          info_qmckl_dgemm_Gz = qmckl_dgemm(context,TransA, TransB, M, N, K, alpha,     &
                                         ao_vgl(:, ielec,  4), LDA, &
                                         coef_normalized(1:ao_num,1:mo_num),size(coef_normalized,1) * 1_8,    &
                                         beta,                                       &
                                         mo_vgl(:,ielec,4),LDC)
          ! Lapl_z
          info_qmckl_dgemm_lap = qmckl_dgemm(context, TransA, TransB, M, N, K, alpha,     &
                                         ao_vgl(:, ielec,  5), LDA, &
                                         coef_normalized(1:ao_num,1:mo_num),size(coef_normalized,1) * 1_8,    &
                                         beta,                                       &
                                         mo_vgl(:,ielec,5),LDC)
  end do

  if(info_qmckl_dgemm_value .eq. QMCKL_SUCCESS .and.  &
     info_qmckl_dgemm_Gx    .eq. QMCKL_SUCCESS .and.  &
     info_qmckl_dgemm_Gy    .eq. QMCKL_SUCCESS .and.  &
     info_qmckl_dgemm_Gz    .eq. QMCKL_SUCCESS .and.  &
     info_qmckl_dgemm_lap   .eq. QMCKL_SUCCESS        ) then
     info = QMCKL_SUCCESS
   else
     info = QMCKL_FAILURE
   end if
  
end function qmckl_compute_mo_basis_vgl_f
    #+end_src

   #+CALL: generate_c_header(table=qmckl_mo_basis_gaussian_vgl_args,rettyp=get_value("CRetType"),fname="qmckl_compute_mo_basis_vgl"))

   #+RESULTS:
   #+begin_src c :tangle (eval h_func) :comments org
   qmckl_exit_code qmckl_compute_mo_basis_vgl (
	 const qmckl_context context,
	 const int64_t ao_num,
	 const int64_t mo_num,
	 const int64_t elec_num,
	 const double* coef_normalized,
	 const double* ao_vgl,
	 double* const mo_vgl ); 
   #+end_src


    #+CALL: generate_c_interface(table=qmckl_mo_basis_gaussian_vgl_args,rettyp=get_value("CRetType"),fname="qmckl_compute_mo_basis_vgl"))

    #+RESULTS:
    #+begin_src f90 :tangle (eval f) :comments org :exports none
    integer(c_int32_t) function qmckl_compute_mo_basis_vgl &
	(context, ao_num, mo_num, elec_num, coef_normalized, ao_vgl, mo_vgl) &
	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 :: ao_num
      integer (c_int64_t) , intent(in)  , value :: mo_num
      integer (c_int64_t) , intent(in)  , value :: elec_num
      real    (c_double ) , intent(in)          :: coef_normalized(ao_num,mo_num)
      real    (c_double ) , intent(in)          :: ao_vgl(ao_num,elec_num,5)
      real    (c_double ) , intent(out)         :: mo_vgl(mo_num,elec_num,5)

      integer(c_int32_t), external :: qmckl_compute_mo_basis_vgl_f
      info = qmckl_compute_mo_basis_vgl_f &
	     (context, ao_num, mo_num, elec_num, coef_normalized, ao_vgl, mo_vgl)

    end function qmckl_compute_mo_basis_vgl
    #+end_src

*** Test

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

def f(a,x,y):
    return np.sum( [c * np.exp( -b*(np.linalg.norm(x-y))**2) for b,c in a] ) 

def df(a,x,y,n):
    h0 = 1.e-6
    if   n == 1: h = np.array([h0,0.,0.])
    elif n == 2: h = np.array([0.,h0,0.])
    elif n == 3: h = np.array([0.,0.,h0])
    return ( f(a,x+h,y) - f(a,x-h,y) ) / (2.*h0)

def d2f(a,x,y,n):
    h0 = 1.e-6
    if   n == 1: h = np.array([h0,0.,0.])
    elif n == 2: h = np.array([0.,h0,0.])
    elif n == 3: h = np.array([0.,0.,h0])
    return ( f(a,x+h,y) - 2.*f(a,x,y) + f(a,x-h,y) ) / h0**2

def lf(a,x,y):
    return d2f(a,x,y,1) + d2f(a,x,y,2) + d2f(a,x,y,3)

elec_26_w1 = np.array( [  1.49050402641, 2.90106987953, -1.05920815468  ] )
elec_15_w2 = np.array( [  -2.20180344582,-1.9113150239,  2.2193744778600002 ] )
nucl_1    = np.array( [ 1.096243353458458e+00, 8.907054016973815e-01, 7.777092280258892e-01 ] )
nucl_2    = np.array( [ 1.168459237342663e+00, 1.125660720053393e+00, 2.833370314829343e+00 ] )

#double prim_vgl[prim_num][5][walk_num][elec_num];
x = elec_26_w1 ; y = nucl_1
a = [(  8.236000E+03,  -1.130000E-04 * 6.1616545431994848e+02 ),
     (  1.235000E+03,  -8.780000E-04 * 1.4847738511079908e+02 ),
     (  2.808000E+02,  -4.540000E-03 * 4.8888635917437597e+01 ),
     (  7.927000E+01,  -1.813300E-02 * 1.8933972232608955e+01 ),
     (  2.559000E+01,  -5.576000E-02 * 8.1089160941724145e+00 ),
     (  8.997000E+00,  -1.268950E-01 * 3.7024003863155635e+00 ),
     (  3.319000E+00,  -1.703520E-01 * 1.7525302846177560e+00 ),
     (  9.059000E-01,   1.403820E-01 * 6.6179013183966806e-01 ),
     (  3.643000E-01,   5.986840E-01 * 3.3419848027174592e-01 ),
     (  1.285000E-01,   3.953890E-01 * 1.5296336817449557e-01 )]

print ( "[1][0][0][26]  : %25.15e"% f(a,x,y))
print ( "[1][1][0][26]  : %25.15e"% df(a,x,y,1))
print ( "[1][2][0][26]  : %25.15e"% df(a,x,y,2))
print ( "[1][3][0][26]  : %25.15e"% df(a,x,y,3))
print ( "[1][4][0][26]  : %25.15e"% lf(a,x,y))

x = elec_15_w2 ; y = nucl_2
a = [(3.387000E+01, 6.068000E-03 *1.0006253235944540e+01),
     (5.095000E+00, 4.530800E-02 *2.4169531573445120e+00),
     (1.159000E+00, 2.028220E-01 *7.9610924849766440e-01),
     (3.258000E-01, 5.039030E-01 *3.0734305383061117e-01),
     (1.027000E-01, 3.834210E-01 *1.2929684417481876e-01)]

print ( "[0][1][15][14] : %25.15e"% f(a,x,y))
print ( "[1][1][15][14] : %25.15e"% df(a,x,y,1))
print ( "[2][1][15][14] : %25.15e"% df(a,x,y,2))
print ( "[3][1][15][14] : %25.15e"% df(a,x,y,3))
print ( "[4][1][15][14] : %25.15e"% lf(a,x,y))

    #+end_src

     #+begin_src c :tangle (eval c_test) :exports none
{
#define walk_num chbrclf_walk_num
#define elec_num chbrclf_elec_num
#define shell_num chbrclf_shell_num
#define ao_num chbrclf_ao_num

int64_t elec_up_num   = chbrclf_elec_up_num;
int64_t elec_dn_num   = chbrclf_elec_dn_num;
double* elec_coord    = &(chbrclf_elec_coord[0][0][0]);
const int64_t   nucl_num      = chbrclf_nucl_num;
const double*   nucl_charge   = chbrclf_charge;
const double*   nucl_coord    = &(chbrclf_nucl_coord[0][0]);

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

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

assert(qmckl_electron_provided(context));

rc = qmckl_set_electron_coord (context, 'N', elec_coord);                                     
assert(rc == QMCKL_SUCCESS);

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

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

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

assert(qmckl_nucleus_provided(context));

const int64_t *  nucleus_index     =  &(chbrclf_basis_nucleus_index[0]);
const int64_t *  nucleus_shell_num =  &(chbrclf_basis_nucleus_shell_num[0]);
const int32_t *  shell_ang_mom     =  &(chbrclf_basis_shell_ang_mom[0]);
const int64_t *  shell_prim_num    =  &(chbrclf_basis_shell_prim_num[0]);
const int64_t *  shell_prim_index  =  &(chbrclf_basis_shell_prim_index[0]);
const double  *  shell_factor      =  &(chbrclf_basis_shell_factor[0]);
const double  *  exponent          =  &(chbrclf_basis_exponent[0]);
const double  *  coefficient       =  &(chbrclf_basis_coefficient[0]);
const double  *  prim_factor       =  &(chbrclf_basis_prim_factor[0]);
const double  *  ao_factor         =  &(chbrclf_basis_ao_factor[0]);

const char typ = 'G';

assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_type (context, typ);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_shell_num (context, chbrclf_shell_num);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_prim_num (context, chbrclf_prim_num);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_nucleus_index (context, nucleus_index);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_nucleus_shell_num (context, nucleus_shell_num);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_shell_ang_mom (context, shell_ang_mom);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_shell_factor  (context, shell_factor);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_shell_prim_num (context, shell_prim_num);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_shell_prim_index (context, shell_prim_index);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_exponent      (context, exponent);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_coefficient   (context, coefficient);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_ao_basis_provided(context));

rc = qmckl_set_ao_basis_prim_factor (context, prim_factor);
assert(rc == QMCKL_SUCCESS);

rc = qmckl_set_ao_basis_ao_num(context, chbrclf_ao_num);
assert(rc == QMCKL_SUCCESS);

rc = qmckl_set_ao_basis_ao_factor (context, ao_factor);
assert(rc == QMCKL_SUCCESS);

assert(qmckl_ao_basis_provided(context));


double ao_vgl[5][walk_num][elec_num][chbrclf_ao_num];

rc = qmckl_get_ao_vgl(context, &(ao_vgl[0][0][0][0]));
assert (rc == QMCKL_SUCCESS);

/* Set up MO data */
const int64_t mo_num = chbrclf_mo_num;
rc = qmckl_set_mo_basis_mo_num(context, mo_num);
assert (rc == QMCKL_SUCCESS);

const double  * mo_coefficient          =  &(chbrclf_mo_coef[0]);

rc = qmckl_set_mo_basis_coefficient(context, mo_coefficient);
assert (rc == QMCKL_SUCCESS);

assert(qmckl_mo_basis_provided(context));

double mo_vgl[5][elec_num][chbrclf_mo_num];
rc = qmckl_get_mo_basis_vgl(context, &(mo_vgl[0][0][0]));
assert (rc == QMCKL_SUCCESS);

// Test overlap of MO
//double point_x[100];
//double point_y[100];
//double point_z[100];
//int32_t npoints=100;
//// obtain points
//double dr = 20./(npoints-1);
//double dr3 = dr*dr*dr;
//
//for (int i=0;i<npoints;++i) {
//  point_x[i] = -10. + dr*i;
//  point_y[i] = -10. + dr*i;
//  point_z[i] = -10. + dr*i;
//}
//
//double ovlmo1 = 0.0;
//// Calculate overlap
//for (int i=0;i<npoints;++i) {
//  printf(".");
//  fflush(stdout);
//  for (int j=0;j<npoints;++j) {
//    for (int k=0;k<npoints;++k) {
//      // Set point
//      elec_coord[0] = point_x[i];
//      elec_coord[1] = point_y[j];
//      elec_coord[2] = point_z[k];
//      rc = qmckl_set_electron_coord (context, 'N', elec_coord);                                     
//      assert(rc == QMCKL_SUCCESS);
//
//      // Calculate value of MO (1st electron)
//      double mo_vgl[5][walk_num][elec_num][chbrclf_mo_num];
//      rc = qmckl_get_mo_basis_vgl(context, &(mo_vgl[0][0][0][0]));
//      assert (rc == QMCKL_SUCCESS);
//      ovlmo1 += mo_vgl[0][0][0][0]*mo_vgl[0][0][0][0]*dr3;
//    }
//  }
//}
//printf("OVL MO1 = %10.15f\n",ovlmo1);


printf("\n");
printf(" mo_vgl mo_vgl[0][26][219] %25.15e\n", mo_vgl[0][2][3]);
printf(" mo_vgl mo_vgl[1][26][219] %25.15e\n", mo_vgl[1][2][3]);
printf(" mo_vgl mo_vgl[0][26][220] %25.15e\n", mo_vgl[0][2][3]);
printf(" mo_vgl mo_vgl[1][26][220] %25.15e\n", mo_vgl[1][2][3]);
printf(" mo_vgl mo_vgl[0][26][221] %25.15e\n", mo_vgl[0][2][3]);
printf(" mo_vgl mo_vgl[1][26][221] %25.15e\n", mo_vgl[1][2][3]);
printf(" mo_vgl mo_vgl[0][26][222] %25.15e\n", mo_vgl[0][2][3]);
printf(" mo_vgl mo_vgl[1][26][222] %25.15e\n", mo_vgl[1][2][3]);
printf(" mo_vgl mo_vgl[0][26][223] %25.15e\n", mo_vgl[0][2][3]);
printf(" mo_vgl mo_vgl[1][26][223] %25.15e\n", mo_vgl[1][2][3]);
printf(" mo_vgl mo_vgl[0][26][224] %25.15e\n", mo_vgl[0][2][3]);
printf(" mo_vgl mo_vgl[1][26][224] %25.15e\n", mo_vgl[1][2][3]);
printf("\n");
}  
 
     #+end_src

* End of files                                                     :noexport:

  #+begin_src c :tangle (eval h_private_type)
#endif
  #+end_src

*** Test
  #+begin_src c :tangle (eval c_test)
    rc = qmckl_context_destroy(context);
    assert (rc == QMCKL_SUCCESS);

    return 0;
}
  #+end_src

*** Compute file names
    #+begin_src emacs-lisp
; The following is required to compute the file names

(setq pwd (file-name-directory buffer-file-name))
(setq name (file-name-nondirectory (substring buffer-file-name 0 -4)))
(setq f  (concat pwd name "_f.f90"))
(setq fh (concat pwd name "_fh.f90"))
(setq c  (concat pwd name ".c"))
(setq h  (concat name ".h"))
(setq h_private  (concat name "_private.h"))
(setq c_test  (concat pwd "test_" name ".c"))
(setq f_test  (concat pwd "test_" name "_f.f90"))

; Minted
(require 'ox-latex)
(setq org-latex-listings 'minted)
(add-to-list 'org-latex-packages-alist '("" "listings"))
(add-to-list 'org-latex-packages-alist '("" "color"))

    #+end_src


# -*- mode: org -*-
# vim: syntax=c