mirror of
https://github.com/pfloos/quack
synced 2024-06-02 11:25:28 +02:00
90 lines
1.7 KiB
Fortran
90 lines
1.7 KiB
Fortran
subroutine linear_response_B_pp(ispin,nBas,nC,nO,nV,nR,nOO,nVV,e,ERI,B_pp)
|
|
|
|
! Compute the B matrix of the pp channel
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
integer,intent(in) :: ispin
|
|
integer,intent(in) :: nBas,nC,nO,nV,nR,nOO,nVV
|
|
double precision,intent(in) :: e(nBas),ERI(nBas,nBas,nBas,nBas)
|
|
|
|
! Local variables
|
|
|
|
double precision,external :: Kronecker_delta
|
|
integer :: a,b,i,j,ab,ij
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: B_pp(nVV,nOO)
|
|
|
|
! Build B matrix for the singlet manifold
|
|
|
|
if(ispin == 1) then
|
|
|
|
ab = 0
|
|
do a=nO+1,nBas-nR
|
|
do b=a,nBas-nR
|
|
ab = ab + 1
|
|
ij = 0
|
|
do i=nC+1,nO
|
|
do j=i,nO
|
|
ij = ij + 1
|
|
|
|
B_pp(ab,ij) = (ERI(a,b,i,j) + ERI(a,b,j,i))/sqrt((1d0 + Kronecker_delta(a,b))*(1d0 + Kronecker_delta(i,j)))
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
! Build the alpha-beta block of the B matrix
|
|
|
|
if(ispin == 3) then
|
|
|
|
ab = 0
|
|
do a=nO+1,nBas-nR
|
|
do b=nO+1,nBas-nR
|
|
ab = ab + 1
|
|
ij = 0
|
|
do i=nC+1,nO
|
|
do j=nC+1,nO
|
|
ij = ij + 1
|
|
|
|
B_pp(ab,ij) = ERI(a,b,i,j)
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
! Build the B matrix for the triplet manifold, or alpha-alpha, or in the spin-orbital basis
|
|
|
|
if(ispin == 2 .or. ispin == 4) then
|
|
|
|
ab = 0
|
|
do a=nO+1,nBas-nR
|
|
do b=a+1,nBas-nR
|
|
ab = ab + 1
|
|
ij = 0
|
|
do i=nC+1,nO
|
|
do j=i+1,nO
|
|
ij = ij + 1
|
|
|
|
B_pp(ab,ij) = ERI(a,b,i,j) - ERI(a,b,j,i)
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
end subroutine linear_response_B_pp
|