mirror of
https://github.com/pfloos/quack
synced 2024-11-13 17:43:58 +01:00
102 lines
2.1 KiB
Fortran
102 lines
2.1 KiB
Fortran
subroutine linear_response_A_matrix(ispin,dRPA,nBas,nC,nO,nV,nR,nS,lambda,e,ERI,A_lr)
|
|
|
|
! Compute linear response
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
logical,intent(in) :: dRPA
|
|
integer,intent(in) :: ispin,nBas,nC,nO,nV,nR,nS
|
|
double precision,intent(in) :: lambda
|
|
double precision,intent(in) :: e(nBas)
|
|
double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
|
|
|
|
! Local variables
|
|
|
|
double precision :: delta_dRPA
|
|
double precision,external :: Kronecker_delta
|
|
|
|
integer :: i,j,a,b,ia,jb
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: A_lr(nS,nS)
|
|
|
|
! Direct RPA
|
|
|
|
delta_dRPA = 0d0
|
|
if(dRPA) delta_dRPA = 1d0
|
|
|
|
! Build A matrix for single manifold
|
|
|
|
if(ispin == 1) then
|
|
|
|
ia = 0
|
|
do i=nC+1,nO
|
|
do a=nO+1,nBas-nR
|
|
ia = ia + 1
|
|
jb = 0
|
|
do j=nC+1,nO
|
|
do b=nO+1,nBas-nR
|
|
jb = jb + 1
|
|
|
|
A_lr(ia,jb) = (e(a) - e(i))*Kronecker_delta(i,j)*Kronecker_delta(a,b) &
|
|
+ 2d0*lambda*ERI(i,b,a,j) - (1d0 - delta_dRPA)*lambda*ERI(i,b,j,a)
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
! Build A matrix for triplet manifold
|
|
|
|
if(ispin == 2) then
|
|
|
|
ia = 0
|
|
do i=nC+1,nO
|
|
do a=nO+1,nBas-nR
|
|
ia = ia + 1
|
|
jb = 0
|
|
do j=nC+1,nO
|
|
do b=nO+1,nBas-nR
|
|
jb = jb + 1
|
|
|
|
A_lr(ia,jb) = (e(a) - e(i))*Kronecker_delta(i,j)*Kronecker_delta(a,b) &
|
|
- (1d0 - delta_dRPA)*lambda*ERI(i,b,j,a)
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
! Build A matrix for spin orbitals
|
|
|
|
if(ispin == 3) then
|
|
|
|
ia = 0
|
|
do i=nC+1,nO
|
|
do a=nO+1,nBas-nR
|
|
ia = ia + 1
|
|
jb = 0
|
|
do j=nC+1,nO
|
|
do b=nO+1,nBas-nR
|
|
jb = jb + 1
|
|
|
|
A_lr(ia,jb) = (e(a) - e(i))*Kronecker_delta(i,j)*Kronecker_delta(a,b) &
|
|
+ lambda*ERI(i,b,a,j) - (1d0 - delta_dRPA)*lambda*ERI(i,b,j,a)
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
end subroutine linear_response_A_matrix
|