4
1
mirror of https://github.com/pfloos/quack synced 2024-11-09 15:43:56 +01:00
quack/src/MBPT/self_energy_correlation.f90

101 lines
2.2 KiB
Fortran
Raw Normal View History

2020-09-24 11:56:06 +02:00
subroutine self_energy_correlation(COHSEX,eta,nBas,nC,nO,nV,nR,nS,e,Omega,rho,EcGM,SigC)
2019-03-19 10:13:33 +01:00
! Compute correlation part of the self-energy
implicit none
include 'parameters.h'
! Input variables
2019-09-22 21:15:53 +02:00
logical,intent(in) :: COHSEX
double precision,intent(in) :: eta
2019-03-19 10:13:33 +01:00
integer,intent(in) :: nBas,nC,nO,nV,nR,nS
2019-09-22 21:15:53 +02:00
double precision,intent(in) :: e(nBas)
double precision,intent(in) :: Omega(nS)
double precision,intent(in) :: rho(nBas,nBas,nS)
2019-03-19 10:13:33 +01:00
! Local variables
2019-07-15 14:19:45 +02:00
integer :: i,j,a,b,p,x,y,jb
2019-09-22 21:15:53 +02:00
double precision :: eps
2019-03-19 10:13:33 +01:00
! Output variables
double precision,intent(out) :: SigC(nBas,nBas)
double precision,intent(out) :: EcGM
! Initialize
SigC = 0d0
2020-09-24 11:56:06 +02:00
!-----------------------------!
! COHSEX static approximation !
!-----------------------------!
2019-03-19 10:13:33 +01:00
if(COHSEX) then
2019-07-15 14:19:45 +02:00
! COHSEX: SEX of the COHSEX correlation self-energy
2019-03-19 10:13:33 +01:00
do x=nC+1,nBas-nR
do y=nC+1,nBas-nR
do i=nC+1,nO
2020-09-21 23:04:26 +02:00
do jb=1,nS
SigC(x,y) = SigC(x,y) + 4d0*rho(x,i,jb)*rho(y,i,jb)/Omega(jb)
2019-03-19 10:13:33 +01:00
enddo
enddo
enddo
enddo
2019-07-15 14:19:45 +02:00
! COHSEX: COH part of the COHSEX correlation self-energy
2019-03-19 10:13:33 +01:00
do x=nC+1,nBas-nR
do y=nC+1,nBas-nR
2019-07-15 14:19:45 +02:00
do p=nC+1,nBas-nR
2020-09-21 23:04:26 +02:00
do jb=1,nS
SigC(x,y) = SigC(x,y) - 2d0*rho(x,p,jb)*rho(y,p,jb)/Omega(jb)
2019-03-19 10:13:33 +01:00
enddo
enddo
enddo
enddo
2019-04-01 15:53:39 +02:00
EcGM = 0d0
2019-03-19 10:13:33 +01:00
do i=nC+1,nO
2019-05-04 17:13:50 +02:00
EcGM = EcGM + 0.5d0*SigC(i,i)
2019-03-19 10:13:33 +01:00
enddo
else
2020-09-24 11:56:06 +02:00
!----------------!
! GW self-energy !
!----------------!
2019-03-19 10:13:33 +01:00
! Occupied part of the correlation self-energy
do x=nC+1,nBas-nR
do y=nC+1,nBas-nR
do i=nC+1,nO
2020-09-21 23:04:26 +02:00
do jb=1,nS
eps = e(x) - e(i) + Omega(jb)
SigC(x,y) = SigC(x,y) + 2d0*rho(x,i,jb)*rho(y,i,jb)*eps/(eps**2 + eta**2)
2019-03-19 10:13:33 +01:00
enddo
enddo
enddo
enddo
! Virtual part of the correlation self-energy
do x=nC+1,nBas-nR
do y=nC+1,nBas-nR
do a=nO+1,nBas-nR
2020-09-21 23:04:26 +02:00
do jb=1,nS
eps = e(x) - e(a) - Omega(jb)
SigC(x,y) = SigC(x,y) + 2d0*rho(x,a,jb)*rho(y,a,jb)*eps/(eps**2 + eta**2)
2019-03-19 10:13:33 +01:00
enddo
enddo
enddo
enddo
endif
end subroutine self_energy_correlation