mirror of
https://github.com/pfloos/quack
synced 2024-12-26 22:33:50 +01:00
51 lines
1.1 KiB
Fortran
51 lines
1.1 KiB
Fortran
|
subroutine S51_lda_exchange_potential(nGrid,weight,nBas,AO,rho,Fx)
|
||
|
|
|
||
|
|
! Compute Slater's LDA exchange potential
|
||
|
|
|
||
|
|
implicit none
|
||
|
|
include 'parameters.h'
|
||
|
|
|
||
|
|
! Input variables
|
||
|
|
|
||
|
|
integer,intent(in) :: nGrid
|
||
|
|
double precision,intent(in) :: weight(nGrid)
|
||
|
|
integer,intent(in) :: nBas
|
||
|
|
double precision,intent(in) :: AO(nBas,nGrid)
|
||
|
|
double precision,intent(in) :: rho(nGrid)
|
||
|
|
|
||
|
|
! Local variables
|
||
|
|
|
||
|
|
integer :: mu,nu,iG
|
||
|
|
double precision :: alpha
|
||
|
|
double precision :: r,vAO
|
||
|
|
|
||
|
|
! Output variables
|
||
|
|
|
||
|
|
double precision,intent(out) :: Fx(nBas,nBas)
|
||
|
|
|
||
|
|
! Cx coefficient for Slater LDA exchange
|
||
|
|
|
||
|
|
alpha = -(3d0/2d0)*(3d0/(4d0*pi))**(1d0/3d0)
|
||
|
|
|
||
|
|
! Compute LDA exchange matrix in the AO basis
|
||
|
|
|
||
|
|
Fx(:,:) = 0d0
|
||
|
|
do mu=1,nBas
|
||
|
|
do nu=1,nBas
|
||
|
|
do iG=1,nGrid
|
||
|
|
|
||
|
|
r = max(0d0,rho(iG))
|
||
|
|
|
||
|
|
if(r > threshold) then
|
||
|
|
|
||
|
|
vAO = weight(iG)*AO(mu,iG)*AO(nu,iG)
|
||
|
|
Fx(mu,nu) = Fx(mu,nu) + vAO*4d0/3d0*alpha*r**(1d0/3d0)
|
||
|
|
|
||
|
|
endif
|
||
|
|
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
|
||
|
|
end subroutine S51_lda_exchange_potential
|