mirror of
https://github.com/pfloos/quack
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88 lines
2.1 KiB
Fortran
88 lines
2.1 KiB
Fortran
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subroutine regularized_renormalization_factor(COHSEX,eta,nBas,nC,nO,nV,nR,nS,e,Omega,rho,Z)
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! Compute the regularized version of the GW renormalization factor
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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 :: i,a,p,jb
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double precision :: eps
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double precision :: kappa
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double precision :: fk,dfk
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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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!-----------------------------------------!
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! Parameters for regularized calculations !
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!-----------------------------------------!
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kappa = 1.1d0
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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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fk = (1d0 - exp(-kappa*abs(eps)))**2/eps
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dfk = - 1d0/eps + 2d0*kappa*exp(-kappa*abs(eps))/(1d0 - exp(-kappa*abs(eps)))
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dfk = dfk*fk
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Z(p) = Z(p) - 2d0*rho(p,i,jb)**2*dfk
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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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fk = (1d0 - exp(-kappa*abs(eps)))**2/eps
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dfk = - 1d0/eps + 2d0*kappa*exp(-kappa*abs(eps))/(1d0 - exp(-kappa*abs(eps)))
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dfk = dfk*fk
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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 regularized_renormalization_factor
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