mirror of https://github.com/pfloos/quack
65 lines
1.5 KiB
Fortran
65 lines
1.5 KiB
Fortran
subroutine GW_phBSE_dynamic_kernel_B(eta,nBas,nC,nO,nV,nR,nS,lambda,eGW,OmRPA,rho,KB)
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! Compute the dynamic part of the Bethe-Salpeter equation matrices
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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) :: 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) :: nS
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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) :: eGW(nBas)
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double precision,intent(in) :: OmRPA(nS)
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double precision,intent(in) :: rho(nBas,nBas,nS)
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! Local variables
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double precision :: chi,eps
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integer :: i,j,a,b,ia,jb,kc
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! Output variables
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double precision,intent(out) :: KB(nS,nS)
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! Initialization
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KB(:,:) = 0d0
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! Build dynamic A matrix
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ia = 0
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do i=nC+1,nO
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do a=nO+1,nBas-nR
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ia = ia + 1
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jb = 0
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do j=nC+1,nO
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do b=nO+1,nBas-nR
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jb = jb + 1
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chi = 0d0
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do kc=1,nS
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eps = - OmRPA(kc) - (eGW(b) - eGW(i))
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chi = chi + rho(i,b,kc)*rho(j,a,kc)*eps/(eps**2 + eta**2)
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eps = - OmRPA(kc) - (eGW(a) - eGW(j))
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chi = chi + rho(i,b,kc)*rho(j,a,kc)*eps/(eps**2 + eta**2)
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end do
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KB(ia,jb) = KB(ia,jb) - 2d0*lambda*chi
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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 subroutine
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