58 KiB
Electrons
In conventional QMC simulations, up-spin and down-spin electrons are
different. The electron
data structure contains the number of
up-spin and down-spin electrons, and the electron coordinates.
Context
The following data stored in the context:
uninitialized |
int32_t | Keeps bit set for uninitialized data |
num |
int64_t | Total number of electrons |
up_num |
int64_t | Number of up-spin electrons |
down_num |
int64_t | Number of down-spin electrons |
walk_num |
int64_t | Number of walkers |
kappa_ee |
double | The distance scaling factor |
kappa_en |
double | The distance scaling factor |
provided |
bool | If true, electron is valid |
coord_new |
double[walk_num][3][num] | New set of electron coordinates |
coord_old |
double[walk_num][3][num] | Old set of electron coordinates |
coord_new_date |
uint64_t | Last modification date of the coordinates |
ee_distance |
double[walk_num][num][num] | Electron-electron distances |
ee_distance_date |
uint64_t | Last modification date of the electron-electron distances |
en_distance |
double[walk_num][nucl_num][num] | Electron-nucleus distances |
en_distance_date |
uint64_t | Last modification date of the electron-electron distances |
ee_distance_rescaled |
double[walk_num][num][num] | Electron-electron distances |
ee_distance_rescaled_date |
uint64_t | Last modification date of the electron-electron distances |
en_distance_rescaled |
double[walk_num][nucl_num][num] | Electron-nucleus distances |
en_distance_rescaled_date |
uint64_t | Last modification date of the electron-electron distances |
Data structure
typedef struct qmckl_electron_struct {
int64_t num;
int64_t up_num;
int64_t down_num;
int64_t walk_num;
double kappa_ee;
double kappa_en;
int64_t coord_new_date;
int64_t ee_distance_date;
int64_t en_distance_date;
int64_t ee_distance_rescaled_date;
int64_t en_distance_rescaled_date;
double* coord_new;
double* coord_old;
double* ee_distance;
double* en_distance;
double* ee_distance_rescaled;
double* en_distance_rescaled;
int32_t uninitialized;
bool provided;
} qmckl_electron_struct;
The uninitialized
integer contains one bit set to one for each
initialization function which has not bee called. It becomes equal
to zero after all initialization functions have been called. The
struct is then initialized and provided == true
.
When all the data relative to electrons have been set, the
following function returns true
.
bool qmckl_electron_provided (const qmckl_context context);
Access functions
Access functions return QMCKL_SUCCESS
when the data has been
successfully retrieved. It returnes QMCKL_INVALID_CONTEXT
when
the context is not a valid context, and QMCKL_NOT_PROVIDED
when
the data has not been provided. If the function returns
successfully, the variable pointed by the pointer given in argument
contains the requested data. Otherwise, this variable is untouched.
#+NAME:post
Number of electrons
Number of walkers
A walker is a set of electron coordinates that are arguments of
the wave function. walk_num
is the number of walkers.
Scaling factors Kappa
Electron coordinates
Returns the current electron coordinates. The pointer is assumed
to point on a memory block of size 3 * elec_num * walk_num
.
The order of the indices is:
Normal | Transposed | |
---|---|---|
C | [walk_num][elec_num][3] |
[walk_num][3][elec_num] |
Fortran | (3,elec_num,walk_num) |
(elec_num,3,walk_num) |
Initialization functions
To set the data relative to the electrons in the context, the
following functions need to be called. When the data structure is
initialized, the internal coord_new
and coord_old
arrays are
both allocated.
qmckl_exit_code qmckl_set_electron_num (qmckl_context context, const int64_t up_num, const int64_t down_num);
qmckl_exit_code qmckl_set_kappa (qmckl_context context, const double kappa_ee, const double kappa_en);
qmckl_exit_code qmckl_set_electron_walk_num (qmckl_context context, const int64_t walk_num);
qmckl_exit_code qmckl_set_electron_coord (qmckl_context context, const char transp, const double* coord);
#+NAME:pre2
#+NAME:post2
To set the number of electrons, we give the number of up-spin and down-spin electrons to the context and we set the number of walkers.
The following function sets the number of walkers.
Next we set the rescale parameter for the rescaled distance metric.
The following function sets the electron coordinates of all the walkers. When this is done, the pointers to the old and new sets of coordinates are swapped, and the new coordinates are overwritten. This can be done only when the data relative to electrons have been set.
Important: changing the electron coordinates increments the date in the context.
Test
/* Reference input data */
int64_t walk_num = chbrclf_walk_num;
int64_t elec_num = chbrclf_elec_num;
int64_t elec_up_num = chbrclf_elec_up_num;
int64_t elec_dn_num = chbrclf_elec_dn_num;
double kappa_ee = 1.0; // TODO Get kappa_ee from chbrclf
double kappa_en = 1.0; // TODO Get kappa_en from chbrclf
double* elec_coord = &(chbrclf_elec_coord[0][0][0]);
int64_t nucl_num = chbrclf_nucl_num;
double* charge = chbrclf_charge;
double* nucl_coord = &(chbrclf_nucl_coord[0][0]);
double nucl_kappa = 1.0; // TODO Change get kappa from chbrclf example
/* --- */
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;
double k_en;
rc = qmckl_get_kappa_ee (context, &k_ee);
assert(rc == QMCKL_NOT_PROVIDED);
rc = qmckl_get_kappa_en (context, &k_en);
assert(rc == QMCKL_NOT_PROVIDED);
rc = qmckl_set_kappa (context, kappa_ee, kappa_en);
assert(rc == QMCKL_SUCCESS);
assert(!qmckl_electron_provided(context));
rc = qmckl_get_kappa_ee (context, &k_ee);
assert(rc == QMCKL_SUCCESS);
assert(k_ee == kappa_ee);
rc = qmckl_get_kappa_en (context, &k_en);
assert(rc == QMCKL_SUCCESS);
assert(k_en == 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);
assert(rc == QMCKL_SUCCESS);
double elec_coord2[walk_num*3*elec_num];
rc = qmckl_get_electron_coord (context, 'N', elec_coord2);
assert(rc == QMCKL_SUCCESS);
for (int64_t i=0 ; i<3*elec_num ; ++i) {
assert( elec_coord[i] == elec_coord2[i] );
}
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.
Electron-electron distances
Get
qmckl_exit_code qmckl_get_electron_ee_distance(qmckl_context context, double* const distance);
Compute
qmckl_context | context | in | Global state |
int64_t | elec_num | in | Number of electrons |
int64_t | walk_num | in | Number of walkers |
double | coord[walk_num][3][elec_num] | in | Electron coordinates |
double | ee_distance[walk_num][elec_num][elec_num] | out | Electron-electron distances |
integer function qmckl_compute_ee_distance_f(context, elec_num, walk_num, coord, ee_distance) &
result(info)
use qmckl
implicit none
integer(qmckl_context), intent(in) :: context
integer*8 , intent(in) :: elec_num
integer*8 , intent(in) :: walk_num
double precision , intent(in) :: coord(elec_num,3,walk_num)
double precision , intent(out) :: ee_distance(elec_num,elec_num,walk_num)
integer*8 :: k
info = QMCKL_SUCCESS
if (context == QMCKL_NULL_CONTEXT) then
info = QMCKL_INVALID_CONTEXT
return
endif
if (elec_num <= 0) then
info = QMCKL_INVALID_ARG_2
return
endif
if (walk_num <= 0) then
info = QMCKL_INVALID_ARG_3
return
endif
do k=1,walk_num
info = qmckl_distance(context, 'T', 'T', elec_num, elec_num, &
coord(1,1,k), elec_num, &
coord(1,1,k), elec_num, &
ee_distance(1,1,k), elec_num)
if (info /= QMCKL_SUCCESS) then
exit
endif
end do
end function qmckl_compute_ee_distance_f
Test
assert(qmckl_electron_provided(context));
double ee_distance[walk_num * elec_num * elec_num];
rc = qmckl_get_electron_ee_distance(context, ee_distance);
// (e1,e2,w)
// (0,0,0) == 0.
assert(ee_distance[0] == 0.);
// (1,0,0) == (0,1,0)
assert(ee_distance[1] == ee_distance[elec_num]);
// value of (1,0,0)
assert(fabs(ee_distance[1]-7.152322512964209) < 1.e-12);
// (0,0,1) == 0.
assert(ee_distance[elec_num*elec_num] == 0.);
// (1,0,1) == (0,1,1)
assert(ee_distance[elec_num*elec_num+1] == ee_distance[elec_num*elec_num+elec_num]);
// value of (1,0,1)
assert(fabs(ee_distance[elec_num*elec_num+1]-6.5517646321055665) < 1.e-12);
Electron-electron rescaled distances
Get
qmckl_exit_code qmckl_get_electron_ee_distance_rescaled(qmckl_context context, double* const distance_rescaled);
Compute
qmckl_context | context | in | Global state |
int64_t | elec_num | in | Number of electrons |
double | kappa_ee | in | Factor to rescale ee distances |
int64_t | walk_num | in | Number of walkers |
double | coord[walk_num][3][elec_num] | in | Electron coordinates |
double | ee_distance[walk_num][elec_num][elec_num] | out | Electron-electron distances |
integer function qmckl_compute_ee_distance_rescaled_f(context, elec_num, kappa_ee, walk_num, coord, ee_distance_rescaled) &
result(info)
use qmckl
implicit none
integer(qmckl_context), intent(in) :: context
integer*8 , intent(in) :: elec_num
double precision , intent(in) :: kappa_ee
integer*8 , intent(in) :: walk_num
double precision , intent(in) :: coord(elec_num,3,walk_num)
double precision , intent(out) :: ee_distance_rescaled(elec_num,elec_num,walk_num)
integer*8 :: k
info = QMCKL_SUCCESS
if (context == QMCKL_NULL_CONTEXT) then
info = QMCKL_INVALID_CONTEXT
return
endif
if (elec_num <= 0) then
info = QMCKL_INVALID_ARG_2
return
endif
if (walk_num <= 0) then
info = QMCKL_INVALID_ARG_3
return
endif
do k=1,walk_num
info = qmckl_distance_rescaled(context, 'T', 'T', elec_num, elec_num, &
coord(1,1,k), elec_num, &
coord(1,1,k), elec_num, &
ee_distance_rescaled(1,1,k), elec_num, kappa_ee)
if (info /= QMCKL_SUCCESS) then
exit
endif
end do
end function qmckl_compute_ee_distance_rescaled_f
Test
assert(qmckl_electron_provided(context));
double ee_distance_rescaled[walk_num * elec_num * elec_num];
rc = qmckl_get_electron_ee_distance_rescaled(context, ee_distance);
// TODO: Get exact values
//// (e1,e2,w)
//// (0,0,0) == 0.
//assert(ee_distance[0] == 0.);
//
//// (1,0,0) == (0,1,0)
//assert(ee_distance[1] == ee_distance[elec_num]);
//
//// value of (1,0,0)
//assert(fabs(ee_distance[1]-7.152322512964209) < 1.e-12);
//
//// (0,0,1) == 0.
//assert(ee_distance[elec_num*elec_num] == 0.);
//
//// (1,0,1) == (0,1,1)
//assert(ee_distance[elec_num*elec_num+1] == ee_distance[elec_num*elec_num+elec_num]);
//
//// value of (1,0,1)
//assert(fabs(ee_distance[elec_num*elec_num+1]-6.5517646321055665) < 1.e-12);
Electron-nucleus distances
Get
qmckl_exit_code qmckl_get_electron_en_distance(qmckl_context context, double* distance);
Compute
qmckl_context | context | in | Global state |
int64_t | elec_num | in | Number of electrons |
int64_t | nucl_num | in | Number of nuclei |
int64_t | walk_num | in | Number of walkers |
double | elec_coord[walk_num][3][elec_num] | in | Electron coordinates |
double | nucl_coord[3][elec_num] | in | Nuclear coordinates |
double | en_distance[walk_num][nucl_num][elec_num] | out | Electron-nucleus distances |
integer function qmckl_compute_en_distance_f(context, elec_num, nucl_num, walk_num, elec_coord, nucl_coord, en_distance) &
result(info)
use qmckl
implicit none
integer(qmckl_context), intent(in) :: context
integer*8 , intent(in) :: elec_num
integer*8 , intent(in) :: nucl_num
integer*8 , intent(in) :: walk_num
double precision , intent(in) :: elec_coord(elec_num,3,walk_num)
double precision , intent(in) :: nucl_coord(nucl_num,3)
double precision , intent(out) :: en_distance(elec_num,nucl_num,walk_num)
integer*8 :: k
info = QMCKL_SUCCESS
if (context == QMCKL_NULL_CONTEXT) then
info = QMCKL_INVALID_CONTEXT
return
endif
if (elec_num <= 0) then
info = QMCKL_INVALID_ARG_2
return
endif
if (nucl_num <= 0) then
info = QMCKL_INVALID_ARG_3
return
endif
if (walk_num <= 0) then
info = QMCKL_INVALID_ARG_4
return
endif
do k=1,walk_num
info = qmckl_distance(context, 'T', 'T', elec_num, nucl_num, &
elec_coord(1,1,k), elec_num, &
nucl_coord, nucl_num, &
en_distance(1,1,k), elec_num)
if (info /= QMCKL_SUCCESS) then
exit
endif
end do
end function qmckl_compute_en_distance_f
Test
assert(!qmckl_nucleus_provided(context));
assert(qmckl_electron_provided(context));
rc = qmckl_set_nucleus_num (context, nucl_num);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_nucleus_kappa (context, nucl_kappa);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_nucleus_charge (context, charge);
assert (rc == QMCKL_SUCCESS);
rc = qmckl_set_nucleus_coord (context, 'T', nucl_coord);
assert (rc == QMCKL_SUCCESS);
assert(qmckl_nucleus_provided(context));
double en_distance[walk_num][nucl_num][elec_num];
rc = qmckl_get_electron_en_distance(context, &(en_distance[0][0][0]));
assert (rc == QMCKL_SUCCESS);
// (e,n,w) in Fortran notation
// (1,1,1)
assert(fabs(en_distance[0][0][0] - 7.546738741619978) < 1.e-12);
// (1,2,1)
assert(fabs(en_distance[0][1][0] - 8.77102435246984) < 1.e-12);
// (2,1,1)
assert(fabs(en_distance[0][0][1] - 3.698922010513608) < 1.e-12);
// (1,1,2)
assert(fabs(en_distance[1][0][0] - 5.824059436060509) < 1.e-12);
// (1,2,2)
assert(fabs(en_distance[1][1][0] - 7.080482110317645) < 1.e-12);
// (2,1,2)
assert(fabs(en_distance[1][0][1] - 3.1804527583077356) < 1.e-12);
Electron-nucleus rescaled distances
Get
qmckl_exit_code qmckl_get_electron_en_distance_rescaled(qmckl_context context, double* distance_rescaled);
Compute
qmckl_context | context | in | Global state |
int64_t | elec_num | in | Number of electrons |
int64_t | nucl_num | in | Number of nuclei |
double | kappa_en | in | The factor for rescaled distances |
int64_t | walk_num | in | Number of walkers |
double | elec_coord[walk_num][3][elec_num] | in | Electron coordinates |
double | nucl_coord[3][elec_num] | in | Nuclear coordinates |
double | en_distance_rescaled_date[walk_num][nucl_num][elec_num] | out | Electron-nucleus distances |
integer function qmckl_compute_en_distance_rescaled_f(context, elec_num, nucl_num, kappa_en, walk_num, elec_coord, &
nucl_coord, en_distance_rescaled) &
result(info)
use qmckl
implicit none
integer(qmckl_context), intent(in) :: context
integer*8 , intent(in) :: elec_num
integer*8 , intent(in) :: nucl_num
double precision , intent(in) :: kappa_en
integer*8 , intent(in) :: walk_num
double precision , intent(in) :: elec_coord(elec_num,3,walk_num)
double precision , intent(in) :: nucl_coord(nucl_num,3)
double precision , intent(out) :: en_distance_rescaled(elec_num,nucl_num,walk_num)
integer*8 :: k
info = QMCKL_SUCCESS
if (context == QMCKL_NULL_CONTEXT) then
info = QMCKL_INVALID_CONTEXT
return
endif
if (elec_num <= 0) then
info = QMCKL_INVALID_ARG_2
return
endif
if (nucl_num <= 0) then
info = QMCKL_INVALID_ARG_3
return
endif
! TODO: comparison with 0
!if (kappa_en <= 0) then
! info = QMCKL_INVALID_ARG_4
! return
!endif
if (walk_num <= 0) then
info = QMCKL_INVALID_ARG_5
return
endif
do k=1,walk_num
info = qmckl_distance_rescaled(context, 'T', 'T', elec_num, nucl_num, &
elec_coord(1,1,k), elec_num, &
nucl_coord, nucl_num, &
en_distance_rescaled(1,1,k), elec_num, kappa_en)
if (info /= QMCKL_SUCCESS) then
exit
endif
end do
end function qmckl_compute_en_distance_rescaled_f
Test
assert(qmckl_electron_provided(context));
rc = qmckl_set_nucleus_num (context, nucl_num);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_nucleus_kappa (context, nucl_kappa);
assert(rc == QMCKL_SUCCESS);
rc = qmckl_set_nucleus_charge (context, charge);
assert (rc == QMCKL_SUCCESS);
rc = qmckl_set_nucleus_coord (context, 'T', nucl_coord);
assert (rc == QMCKL_SUCCESS);
assert(qmckl_nucleus_provided(context));
double en_distance_rescaled[walk_num][nucl_num][elec_num];
rc = qmckl_get_electron_en_distance_rescaled(context, &(en_distance[0][0][0]));
assert (rc == QMCKL_SUCCESS);
// TODO: check exact values
//// (e,n,w) in Fortran notation
//// (1,1,1)
//assert(fabs(en_distance[0][0][0] - 7.546738741619978) < 1.e-12);
//
//// (1,2,1)
//assert(fabs(en_distance[0][1][0] - 8.77102435246984) < 1.e-12);
//
//// (2,1,1)
//assert(fabs(en_distance[0][0][1] - 3.698922010513608) < 1.e-12);
//
//// (1,1,2)
//assert(fabs(en_distance[1][0][0] - 5.824059436060509) < 1.e-12);
//
//// (1,2,2)
//assert(fabs(en_distance[1][1][0] - 7.080482110317645) < 1.e-12);
//
//// (2,1,2)
//assert(fabs(en_distance[1][0][1] - 3.1804527583077356) < 1.e-12);