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https://github.com/pfloos/quack
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73 lines
1.6 KiB
Fortran
73 lines
1.6 KiB
Fortran
subroutine renormalization_factor(COHSEX,eta,nBas,nC,nO,nV,nR,nS,e,Omega,rho,Z)
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! Compute renormalization factor for GW
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implicit none
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include 'parameters.h'
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! Input variables
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logical,intent(in) :: COHSEX
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double precision,intent(in) :: eta
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integer,intent(in) :: nBas
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integer,intent(in) :: nC
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integer,intent(in) :: nO
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integer,intent(in) :: nV
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integer,intent(in) :: nR
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integer,intent(in) :: nS
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double precision,intent(in) :: e(nBas)
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double precision,intent(in) :: Omega(nS)
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double precision,intent(in) :: rho(nBas,nBas,nS)
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! Local variables
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integer :: p,i,a,jb
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double precision :: eps
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! Output variables
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double precision,intent(out) :: Z(nBas)
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! Initialize
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Z(:) = 0d0
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! static COHSEX approximation
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if(COHSEX) then
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Z(:) = 1d0
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return
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else
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! Occupied part of the correlation self-energy
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do p=nC+1,nBas-nR
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do i=nC+1,nO
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do jb=1,nS
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eps = e(p) - e(i) + Omega(jb)
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Z(p) = Z(p) - 2d0*rho(p,i,jb)**2*(eps/(eps**2 + eta**2))**2
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end do
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end do
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end do
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! Virtual part of the correlation self-energy
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do p=nC+1,nBas-nR
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do a=nO+1,nBas-nR
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do jb=1,nS
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eps = e(p) - e(a) - Omega(jb)
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Z(p) = Z(p) - 2d0*rho(p,a,jb)**2*(eps/(eps**2 + eta**2))**2
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end do
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end do
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end do
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end if
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! Compute renormalization factor from derivative of SigC
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Z(:) = 1d0/(1d0 - Z(:))
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end subroutine renormalization_factor
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