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qp2/src/becke_numerical_grid/grid_becke.irp.f
2019-01-25 11:39:31 +01:00

230 lines
7.8 KiB
Fortran

BEGIN_PROVIDER [integer, n_points_radial_grid]
&BEGIN_PROVIDER [integer, n_points_integration_angular]
implicit none
BEGIN_DOC
! n_points_radial_grid = number of radial grid points per atom
!
! n_points_integration_angular = number of angular grid points per atom
!
! These numbers are automatically set by setting the grid_type_sgn parameter
END_DOC
select case (grid_type_sgn)
case(0)
n_points_radial_grid = 23
n_points_integration_angular = 170
case(1)
n_points_radial_grid = 50
n_points_integration_angular = 194
case(2)
n_points_radial_grid = 75
n_points_integration_angular = 302
case(3)
n_points_radial_grid = 99
n_points_integration_angular = 590
case default
write(*,*) '!!! Quadrature grid not available !!!'
stop
end select
END_PROVIDER
BEGIN_PROVIDER [integer, n_points_grid_per_atom]
implicit none
BEGIN_DOC
! Number of grid points per atom
END_DOC
n_points_grid_per_atom = n_points_integration_angular * n_points_radial_grid
END_PROVIDER
BEGIN_PROVIDER [double precision, angular_quadrature_points, (n_points_integration_angular,3) ]
&BEGIN_PROVIDER [double precision, weights_angular_points, (n_points_integration_angular)]
implicit none
BEGIN_DOC
! weights and grid points for the integration on the angular variables on
! the unit sphere centered on (0,0,0)
! According to the LEBEDEV scheme
END_DOC
include 'constants.include.F'
integer :: i
double precision :: accu
double precision :: degre_rad
double precision :: x(n_points_integration_angular)
double precision :: y(n_points_integration_angular)
double precision :: z(n_points_integration_angular)
double precision :: w(n_points_integration_angular)
degre_rad = pi/180.d0
accu = 0.d0
select case (n_points_integration_angular)
case (5810)
call LD5810(X,Y,Z,W,n_points_integration_angular)
case (2030)
call LD2030(X,Y,Z,W,n_points_integration_angular)
case (1202)
call LD1202(X,Y,Z,W,n_points_integration_angular)
case (0590)
call LD0590(X,Y,Z,W,n_points_integration_angular)
case (302)
call LD0302(X,Y,Z,W,n_points_integration_angular)
case (266)
call LD0266(X,Y,Z,W,n_points_integration_angular)
case (194)
call LD0194(X,Y,Z,W,n_points_integration_angular)
case (170)
call LD0170(X,Y,Z,W,n_points_integration_angular)
case (74)
call LD0074(X,Y,Z,W,n_points_integration_angular)
case (50)
call LD0050(X,Y,Z,W,n_points_integration_angular)
case default
print *, irp_here//': wrong n_points_integration_angular. Expected:'
print *, '[ 50 | 74 | 170 | 194 | 266 | 302 | 590 | 1202 | 2030 | 5810 ]'
stop -1
end select
do i = 1, n_points_integration_angular
angular_quadrature_points(i,1) = x(i)
angular_quadrature_points(i,2) = y(i)
angular_quadrature_points(i,3) = z(i)
weights_angular_points(i) = w(i) * 4.d0 * pi
accu += w(i)
enddo
END_PROVIDER
BEGIN_PROVIDER [integer , m_knowles]
implicit none
BEGIN_DOC
! value of the "m" parameter in the equation (7) of the paper of Knowles (JCP, 104, 1996)
END_DOC
m_knowles = 3
END_PROVIDER
BEGIN_PROVIDER [double precision, grid_points_radial, (n_points_radial_grid)]
&BEGIN_PROVIDER [double precision, dr_radial_integral]
implicit none
BEGIN_DOC
! points in [0,1] to map the radial integral [0,\infty]
END_DOC
dr_radial_integral = 1.d0/dble(n_points_radial_grid-1)
integer :: i
do i = 1, n_points_radial_grid
grid_points_radial(i) = dble(i-1) * dr_radial_integral
enddo
END_PROVIDER
BEGIN_PROVIDER [double precision, grid_points_per_atom, (3,n_points_integration_angular,n_points_radial_grid,nucl_num)]
BEGIN_DOC
! x,y,z coordinates of grid points used for integration in 3d space
END_DOC
implicit none
integer :: i,j,k
double precision :: dr,x_ref,y_ref,z_ref
double precision :: knowles_function
do i = 1, nucl_num
x_ref = nucl_coord(i,1)
y_ref = nucl_coord(i,2)
z_ref = nucl_coord(i,3)
do j = 1, n_points_radial_grid-1
double precision :: x,r
! x value for the mapping of the [0, +\infty] to [0,1]
x = grid_points_radial(j)
! value of the radial coordinate for the integration
r = knowles_function(alpha_knowles(int(nucl_charge(i))),m_knowles,x)
! explicit values of the grid points centered around each atom
do k = 1, n_points_integration_angular
grid_points_per_atom(1,k,j,i) = &
x_ref + angular_quadrature_points(k,1) * r
grid_points_per_atom(2,k,j,i) = &
y_ref + angular_quadrature_points(k,2) * r
grid_points_per_atom(3,k,j,i) = &
z_ref + angular_quadrature_points(k,3) * r
enddo
enddo
enddo
END_PROVIDER
BEGIN_PROVIDER [double precision, weight_at_r, (n_points_integration_angular,n_points_radial_grid,nucl_num) ]
BEGIN_DOC
! Weight function at grid points : w_n(r) according to the equation (22)
! of Becke original paper (JCP, 88, 1988)
!
! The "n" discrete variable represents the nucleis which in this array is
! represented by the last dimension and the points are labelled by the
! other dimensions.
END_DOC
implicit none
integer :: i,j,k,l,m
double precision :: r(3)
double precision :: accu,cell_function_becke
double precision :: tmp_array(nucl_num)
! run over all points in space
! that are referred to each atom
do j = 1, nucl_num
!for each radial grid attached to the "jth" atom
do k = 1, n_points_radial_grid -1
! for each angular point attached to the "jth" atom
do l = 1, n_points_integration_angular
r(1) = grid_points_per_atom(1,l,k,j)
r(2) = grid_points_per_atom(2,l,k,j)
r(3) = grid_points_per_atom(3,l,k,j)
accu = 0.d0
! For each of these points in space, ou need to evaluate the P_n(r)
do i = 1, nucl_num
! function defined for each atom "i" by equation (13) and (21) with k == 3
tmp_array(i) = cell_function_becke(r,i) ! P_n(r)
! Then you compute the summ the P_n(r) function for each of the "r" points
accu += tmp_array(i)
enddo
accu = 1.d0/accu
weight_at_r(l,k,j) = tmp_array(j) * accu
enddo
enddo
enddo
END_PROVIDER
BEGIN_PROVIDER [double precision, final_weight_at_r, (n_points_integration_angular,n_points_radial_grid,nucl_num) ]
BEGIN_DOC
! Total weight on each grid point which takes into account all Lebedev, Voronoi and radial weights.
END_DOC
implicit none
integer :: i,j,k,l,m
double precision :: r(3)
double precision :: accu,cell_function_becke
double precision :: tmp_array(nucl_num)
double precision :: contrib_integration,x
double precision :: derivative_knowles_function,knowles_function
! run over all points in space
do j = 1, nucl_num ! that are referred to each atom
do i = 1, n_points_radial_grid -1 !for each radial grid attached to the "jth" atom
x = grid_points_radial(i) ! x value for the mapping of the [0, +\infty] to [0,1]
do k = 1, n_points_integration_angular ! for each angular point attached to the "jth" atom
contrib_integration = derivative_knowles_function(alpha_knowles(int(nucl_charge(j))),m_knowles,x)&
*knowles_function(alpha_knowles(int(nucl_charge(j))),m_knowles,x)**2
final_weight_at_r(k,i,j) = weights_angular_points(k) * weight_at_r(k,i,j) * contrib_integration * dr_radial_integral
enddo
enddo
enddo
END_PROVIDER