mirror of https://github.com/pfloos/quack
138 lines
3.9 KiB
Fortran
138 lines
3.9 KiB
Fortran
subroutine GF2_ppBSE2_static_kernel_C(ispin,eta,nBas,nC,nO,nV,nR,nVV,lambda,ERI,eGF,KC_sta)
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! Compute the resonant part of the static BSE2 matrix
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implicit none
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include 'parameters.h'
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! Input variables
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integer,intent(in) :: ispin
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integer,intent(in) :: nBas
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integer,intent(in) :: nC
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integer,intent(in) :: nO
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integer,intent(in) :: nV
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integer,intent(in) :: nR
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integer,intent(in) :: nVV
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double precision,intent(in) :: eta
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double precision,intent(in) :: lambda
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double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
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double precision,intent(in) :: eGF(nBas)
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! Local variables
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double precision :: dem,num
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integer :: m
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integer :: a,b,c,d,e
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integer :: ab,cd
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! Output variables
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double precision,intent(out) :: KC_sta(nVV,nVV)
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! Initialization
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KC_sta(:,:) = 0d0
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! Second-order correlation kernel for the block C of the singlet manifold
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if(ispin == 1) then
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ab = 0
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do a=nO+1,nBas-nR
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do b=a,nBas-nR
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ab = ab + 1
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cd = 0
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do c=nO+1,nBas-nR
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do d=c,nBas-nR
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cd = cd + 1
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do m=nC+1,nO
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do e=nO+1,nBas-nR
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(a,m,c,e)*ERI(b,e,d,m) - ERI(a,m,c,e)*ERI(b,e,m,d) &
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- ERI(a,m,e,c)*ERI(b,e,d,m) + 2d0*ERI(a,m,e,c)*ERI(b,e,m,d)
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KC_sta(ab,cd) = KC_sta(ab,cd) + 0.5d0*num*dem/(dem**2 + eta**2)
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(b,m,c,e)*ERI(a,e,d,m) - ERI(b,m,c,e)*ERI(a,e,m,d) &
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- ERI(b,m,e,c)*ERI(a,e,d,m) + 2d0*ERI(b,m,e,c)*ERI(a,e,m,d)
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KC_sta(ab,cd) = KC_sta(ab,cd) - 0.5d0*num*dem/(dem**2 + eta**2)
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(a,e,c,m)*ERI(b,m,d,e) - ERI(a,e,c,m)*ERI(b,m,e,d) &
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- ERI(a,e,m,c)*ERI(b,m,d,e) + 2d0*ERI(a,e,m,c)*ERI(b,m,e,d)
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KC_sta(ab,cd) = KC_sta(ab,cd) + 0.5d0*num*dem/(dem**2 + eta**2)
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(b,e,c,m)*ERI(a,m,d,e) - ERI(b,e,c,m)*ERI(a,m,e,d) &
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- ERI(b,e,m,c)*ERI(a,m,d,e) + 2d0*ERI(b,e,c,m)*ERI(a,m,e,d)
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KC_sta(ab,cd) = KC_sta(ab,cd) - 0.5d0*num*dem/(dem**2 + eta**2)
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end do
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end do
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end do
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end do
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end do
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end do
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end if
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! Second-order correlation kernel for the block C of the triplet manifold
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if(ispin == 2) then
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ab = 0
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do a=nO+1,nBas-nR
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do b=a+1,nBas-nR
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ab = ab + 1
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cd = 0
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do c=nO+1,nBas-nR
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do d=c+1,nBas-nR
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cd = cd + 1
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do m=nC+1,nO
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do e=nO+1,nBas-nR
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(a,m,c,e)*ERI(b,e,d,m) - ERI(a,m,c,e)*ERI(b,e,m,d) - ERI(a,m,e,c)*ERI(b,e,d,m)
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KC_sta(ab,cd) = KC_sta(ab,cd) + 0.5d0*num*dem/(dem**2 + eta**2)
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(b,m,c,e)*ERI(a,e,d,m) - ERI(b,m,c,e)*ERI(a,e,m,d) - ERI(b,m,e,c)*ERI(a,e,d,m)
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KC_sta(ab,cd) = KC_sta(ab,cd) - 0.5d0*num*dem/(dem**2 + eta**2)
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(a,e,c,m)*ERI(b,m,d,e) - ERI(a,e,c,m)*ERI(b,m,e,d) - ERI(a,e,m,c)*ERI(b,m,d,e)
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KC_sta(ab,cd) = KC_sta(ab,cd) + 0.5d0*num*dem/(dem**2 + eta**2)
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dem = eGF(m) - eGF(e)
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num = 2d0*ERI(b,e,c,m)*ERI(a,m,d,e) - ERI(b,e,c,m)*ERI(a,m,e,d) - ERI(b,e,m,c)*ERI(a,m,d,e)
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KC_sta(ab,cd) = KC_sta(ab,cd) - 0.5d0*num*dem/(dem**2 + eta**2)
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end do
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end do
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end do
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end do
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end do
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end do
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end if
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end subroutine
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