mirror of
https://github.com/pfloos/quack
synced 2024-11-19 12:32:36 +01:00
91 lines
2.0 KiB
Fortran
91 lines
2.0 KiB
Fortran
subroutine GW_self_energy_diag(eta,nBas,nC,nO,nV,nR,nS,e,Om,rho,EcGM,Sig,Z)
|
|
|
|
! Compute diagonal of the correlation part of the self-energy and the renormalization factor
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
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) :: Om(nS)
|
|
double precision,intent(in) :: rho(nBas,nBas,nS)
|
|
|
|
! Local variables
|
|
|
|
integer :: i,a,p,m
|
|
double precision :: num,eps
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: Sig(nBas)
|
|
double precision,intent(out) :: Z(nBas)
|
|
double precision,intent(out) :: EcGM
|
|
|
|
! Initialize
|
|
|
|
Sig(:) = 0d0
|
|
Z(:) = 0d0
|
|
|
|
!----------------!
|
|
! GW self-energy !
|
|
!----------------!
|
|
|
|
! Occupied part of the correlation self-energy
|
|
|
|
do p=nC+1,nBas-nR
|
|
do i=nC+1,nO
|
|
do m=1,nS
|
|
|
|
eps = e(p) - e(i) + Om(m)
|
|
num = 2d0*rho(p,i,m)**2
|
|
Sig(p) = Sig(p) + num*eps/(eps**2 + eta**2)
|
|
Z(p) = Z(p) - num*(eps**2 - eta**2)/(eps**2 + eta**2)**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 m=1,nS
|
|
|
|
eps = e(p) - e(a) - Om(m)
|
|
num = 2d0*rho(p,a,m)**2
|
|
Sig(p) = Sig(p) + num*eps/(eps**2 + eta**2)
|
|
Z(p) = Z(p) - num*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
! Galitskii-Migdal correlation energy
|
|
|
|
EcGM = 0d0
|
|
do i=nC+1,nO
|
|
do a=nO+1,nBas-nR
|
|
do m=1,nS
|
|
|
|
eps = e(a) - e(i) + Om(m)
|
|
num = 4d0*rho(a,i,m)**2
|
|
EcGM = EcGM - num*eps/(eps**2 + eta**2)
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
! Compute renormalization factor from derivative
|
|
|
|
Z(:) = 1d0/(1d0 - Z(:))
|
|
|
|
end subroutine
|