mirror of
https://github.com/pfloos/quack
synced 2024-08-14 16:48:35 +02:00
86 lines
2.0 KiB
Fortran
86 lines
2.0 KiB
Fortran
subroutine regularized_renormalization_factor(COHSEX,eta,nBas,nC,nO,nV,nR,nS,e,Omega,rho,Z)
|
|
|
|
! Compute the regularized version of the GW renormalization factor
|
|
|
|
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,jb
|
|
double precision :: eps
|
|
|
|
double precision :: kappa
|
|
double precision :: fk,dfk
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: Z(nBas)
|
|
|
|
! Initialize
|
|
|
|
Z(:) = 0d0
|
|
|
|
!-----------------------------------------!
|
|
! Parameters for regularized calculations !
|
|
!-----------------------------------------!
|
|
|
|
kappa = 1d0
|
|
|
|
! static COHSEX approximation
|
|
|
|
if(COHSEX) then
|
|
|
|
Z(:) = 1d0
|
|
return
|
|
|
|
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)
|
|
fk = (1d0 - exp(-2d0*eps**2/kappa**2))/eps
|
|
dfk = - fk/eps + 4d0*kappa**2*exp(-2d0*eps**2/kappa**2)
|
|
Z(p) = Z(p) - 2d0*rho(p,i,jb)**2*dfk
|
|
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)
|
|
fk = (1d0 - exp(-2d0*eps**2/kappa**2))/eps
|
|
dfk = - fk/eps + 4d0*kappa**2*exp(-2d0*eps**2/kappa**2)
|
|
Z(p) = Z(p) - 2d0*rho(p,a,jb)**2*dfk
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
! Compute renormalization factor from derivative of SigC
|
|
|
|
Z(:) = 1d0/(1d0 - Z(:))
|
|
|
|
end subroutine regularized_renormalization_factor
|