mirror of
https://github.com/pfloos/quack
synced 2024-11-19 20:42:44 +01:00
133 lines
2.7 KiB
Fortran
133 lines
2.7 KiB
Fortran
subroutine GW_ppBSE_static_kernel_D(ispin,eta,nBas,nC,nO,nV,nR,nS,nOO,lambda,ERI,Om,rho,KD)
|
|
|
|
! Compute the OOOO block of the static screening W for the pp-BSE
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
integer,intent(in) :: ispin
|
|
integer,intent(in) :: nBas
|
|
integer,intent(in) :: nC
|
|
integer,intent(in) :: nO
|
|
integer,intent(in) :: nV
|
|
integer,intent(in) :: nR
|
|
integer,intent(in) :: nS
|
|
integer,intent(in) :: nOO
|
|
double precision,intent(in) :: eta
|
|
double precision,intent(in) :: lambda
|
|
double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
|
|
double precision,intent(in) :: Om(nS)
|
|
double precision,intent(in) :: rho(nBas,nBas,nS)
|
|
|
|
! Local variables
|
|
|
|
double precision,external :: Kronecker_delta
|
|
double precision :: chi
|
|
double precision :: eps
|
|
integer :: i,j,k,l,ij,kl,m
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: KD(nOO,nOO)
|
|
|
|
! Initialization
|
|
|
|
KD(:,:) = 0d0
|
|
|
|
!---------------!
|
|
! Singlet block !
|
|
!---------------!
|
|
|
|
if(ispin == 1) then
|
|
|
|
ij = 0
|
|
do i=nC+1,nO
|
|
do j=i,nO
|
|
ij = ij + 1
|
|
kl = 0
|
|
do k=nC+1,nO
|
|
do l=k,nO
|
|
kl = kl + 1
|
|
|
|
chi = 0d0
|
|
do m=1,nS
|
|
eps = Om(m)**2 + eta**2
|
|
chi = chi - rho(i,k,m)*rho(j,l,m)*Om(m)/eps &
|
|
+ rho(i,l,m)*rho(j,k,m)*Om(m)/eps
|
|
enddo
|
|
|
|
KD(ij,kl) = 2d0*lambda*chi/sqrt((1d0 + Kronecker_delta(i,j))*(1d0 + Kronecker_delta(k,l)))
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
!---------------!
|
|
! Triplet block !
|
|
!---------------!
|
|
|
|
if(ispin == 2) then
|
|
|
|
ij = 0
|
|
do i=nC+1,nO
|
|
do j=i+1,nO
|
|
ij = ij + 1
|
|
kl = 0
|
|
do k=nC+1,nO
|
|
do l=k+1,nO
|
|
kl = kl + 1
|
|
|
|
chi = 0d0
|
|
do m=1,nS
|
|
eps = Om(m)**2 + eta**2
|
|
chi = chi - rho(i,k,m)*rho(j,l,m)*Om(m)/eps &
|
|
+ rho(i,l,m)*rho(j,k,m)*Om(m)/eps
|
|
enddo
|
|
|
|
KD(ij,kl) = 2d0*lambda*chi
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
!---------------!
|
|
! SpinOrb block !
|
|
!---------------!
|
|
|
|
if(ispin == 4) then
|
|
|
|
ij = 0
|
|
do i=nC+1,nO
|
|
do j=i+1,nO
|
|
ij = ij + 1
|
|
kl = 0
|
|
do k=nC+1,nO
|
|
do l=k+1,nO
|
|
kl = kl + 1
|
|
|
|
chi = 0d0
|
|
do m=1,nS
|
|
eps = Om(m)**2 + eta**2
|
|
chi = chi - rho(i,k,m)*rho(j,l,m)*Om(m)/eps &
|
|
+ rho(i,l,m)*rho(j,k,m)*Om(m)/eps
|
|
enddo
|
|
|
|
KD(ij,kl) = lambda*chi
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
end subroutine
|