mirror of
https://github.com/pfloos/quack
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91 lines
2.2 KiB
Fortran
91 lines
2.2 KiB
Fortran
subroutine regularized_self_energy_GF2(eta,nBas,nC,nO,nV,nR,nS,eHF,eGF2,ERI,SigC,Z)
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! Compute GF2 self-energy and its 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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double precision,intent(in) :: eta
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integer,intent(in) :: nBas,nC,nO,nV,nR,nS
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double precision,intent(in) :: eHF(nBas)
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double precision,intent(in) :: eGF2(nBas)
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double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
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! Local variables
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integer :: i,j,a,b
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integer :: p,q
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double precision :: eps
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double precision :: num
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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) :: SigC(nBas,nBas)
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double precision,intent(out) :: Z(nBas)
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! Initialize
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SigC(:,:) = 0d0
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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 = 1d0
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!----------------------------------------------------!
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! Compute GF2 self-energy and renormalization factor !
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!----------------------------------------------------!
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do p=nC+1,nBas-nR
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do q=nC+1,nBas-nR
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do i=nC+1,nO
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do j=nC+1,nO
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do a=nO+1,nBas-nR
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eps = eGF2(p) + eHF(a) - eHF(i) - eHF(j)
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num = (2d0*ERI(p,a,i,j) - ERI(p,a,j,i))*ERI(q,a,i,j)
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fk = (1d0 - exp(-2d0*eps**2/kappa**2))/eps
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dfk = - fk/eps + 4d0*kappa**2*exp(-2d0*eps**2/kappa**2)
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SigC(p,q) = SigC(p,q) + num*fk
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if(p == q) Z(p) = Z(p) - num*dfk
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end do
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end do
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end do
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end do
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end do
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do p=nC+1,nBas-nR
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do q=nC+1,nBas-nR
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do i=nC+1,nO
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do a=nO+1,nBas-nR
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do b=nO+1,nBas-nR
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eps = eGF2(p) + eHF(i) - eHF(a) - eHF(b)
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num = (2d0*ERI(p,i,a,b) - ERI(p,i,b,a))*ERI(q,i,a,b)
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fk = (1d0 - exp(-2d0*eps**2/kappa**2))/eps
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dfk = - fk/eps + 4d0*kappa**2*exp(-2d0*eps**2/kappa**2)
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SigC(p,q) = SigC(p,q) + num*fk
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if(p == q) Z(p) = Z(p) - num*dfk
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end do
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end do
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end do
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end do
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end do
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Z(:) = 1d0/(1d0 - Z(:))
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end subroutine regularized_self_energy_GF2
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