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mirror of https://github.com/pfloos/quack synced 2024-12-24 21:33:45 +01:00
QuAcK/src/GW/self_energy_correlation_diag.f90

112 lines
2.5 KiB
Fortran

subroutine self_energy_correlation_diag(COHSEX,eta,nBas,nC,nO,nV,nR,nS,e,Omega,rho,EcGM,SigC)
! Compute diagonal of the correlation part of the self-energy
implicit none
include 'parameters.h'
! Input variables
logical,intent(in) :: COHSEX
double precision,intent(in) :: eta
integer,intent(in) :: nBas
integer,intent(in) :: nC
integer,intent(in) :: nO
integer,intent(in) :: nV
integer,intent(in) :: nR
integer,intent(in) :: nS
double precision,intent(in) :: e(nBas)
double precision,intent(in) :: Omega(nS)
double precision,intent(in) :: rho(nBas,nBas,nS)
! Local variables
integer :: i,a,p,q,jb
double precision :: eps
! Output variables
double precision,intent(out) :: SigC(nBas)
double precision,intent(out) :: EcGM
! Initialize
SigC(:) = 0d0
!-----------------------------
! COHSEX static self-energy
!-----------------------------
if(COHSEX) then
! COHSEX: SEX part of the COHSEX correlation self-energy
do p=nC+1,nBas-nR
do i=nC+1,nO
do jb=1,nS
SigC(p) = SigC(p) + 4d0*rho(p,i,jb)**2/Omega(jb)
end do
end do
end do
! COHSEX: COH part of the COHSEX correlation self-energy
do p=nC+1,nBas-nR
do q=nC+1,nBas-nR
do jb=1,nS
SigC(p) = SigC(p) - 2d0*rho(p,q,jb)**2/Omega(jb)
end do
end do
end do
! GM correlation energy
EcGM = 0d0
do i=nC+1,nO
EcGM = EcGM - SigC(i)
end do
!-----------------------------
! GW self-energy
!-----------------------------
else
! Occupied part of the correlation self-energy
do p=nC+1,nBas-nR
do i=nC+1,nO
do jb=1,nS
eps = e(p) - e(i) + Omega(jb)
SigC(p) = SigC(p) + 2d0*rho(p,i,jb)**2*eps/(eps**2 + eta**2)
end do
end do
end do
! Virtual part of the correlation self-energy
do p=nC+1,nBas-nR
do a=nO+1,nBas-nR
do jb=1,nS
eps = e(p) - e(a) - Omega(jb)
SigC(p) = SigC(p) + 2d0*rho(p,a,jb)**2*eps/(eps**2 + eta**2)
end do
end do
end do
! GM correlation energy
EcGM = 0d0
do i=nC+1,nO
do a=nO+1,nBas-nR
do jb=1,nS
eps = e(a) - e(i) + Omega(jb)
EcGM = EcGM - 4d0*rho(a,i,jb)*rho(a,i,jb)*eps/(eps**2 + eta**2)
end do
end do
end do
end if
end subroutine self_energy_correlation_diag