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mirror of https://github.com/pfloos/quack synced 2024-11-19 20:42:44 +01:00
quack/src/GW/Bethe_Salpeter_A_matrix_dynamic.f90

92 lines
2.2 KiB
Fortran

subroutine Bethe_Salpeter_A_matrix_dynamic(eta,nBas,nC,nO,nV,nR,nS,lambda,eGW,OmRPA,rho_RPA,OmBSE,A_dyn,ZA_dyn)
! Compute the dynamic part of the Bethe-Salpeter equation matrices
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: nBas,nC,nO,nV,nR,nS
double precision,intent(in) :: eta
double precision,intent(in) :: lambda
double precision,intent(in) :: eGW(nBas)
double precision,intent(in) :: OmRPA(nS)
double precision,intent(in) :: rho_RPA(nBas,nBas,nS)
double precision,intent(in) :: OmBSE
! Local variables
integer :: maxS
double precision :: chi
double precision :: eps
integer :: i,j,a,b,ia,jb,kc
! Output variables
double precision,intent(out) :: A_dyn(nS,nS)
double precision,intent(out) :: ZA_dyn(nS,nS)
! Initialization
A_dyn(:,:) = 0d0
ZA_dyn(:,:) = 0d0
! Number of poles taken into account
maxS = nS
! Build dynamic A matrix
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
chi = 0d0
do kc=1,maxS
eps = OmRPA(kc)
chi = chi + rho_RPA(i,j,kc)*rho_RPA(a,b,kc)*eps/(eps**2 + eta**2)
enddo
A_dyn(ia,jb) = A_dyn(ia,jb) - 4d0*lambda*chi
chi = 0d0
do kc=1,maxS
eps = + OmBSE - OmRPA(kc) - (eGW(a) - eGW(j))
chi = chi + rho_RPA(i,j,kc)*rho_RPA(a,b,kc)*eps/(eps**2 + eta**2)
eps = + OmBSE - OmRPA(kc) - (eGW(b) - eGW(i))
chi = chi + rho_RPA(i,j,kc)*rho_RPA(a,b,kc)*eps/(eps**2 + eta**2)
enddo
A_dyn(ia,jb) = A_dyn(ia,jb) - 2d0*lambda*chi
chi = 0d0
do kc=1,maxS
eps = + OmBSE - OmRPA(kc) - (eGW(a) - eGW(j))
chi = chi + rho_RPA(i,j,kc)*rho_RPA(a,b,kc)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
eps = + OmBSE - OmRPA(kc) - (eGW(b) - eGW(i))
chi = chi + rho_RPA(i,j,kc)*rho_RPA(a,b,kc)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
enddo
ZA_dyn(ia,jb) = ZA_dyn(ia,jb) + 2d0*lambda*chi
enddo
enddo
enddo
enddo
end subroutine Bethe_Salpeter_A_matrix_dynamic