mirror of https://github.com/pfloos/quack
85 lines
2.4 KiB
Fortran
85 lines
2.4 KiB
Fortran
double precision function SigmaC(p,w,eta,nBas,nC,nO,nV,nR,nS,e,Omega,rho,regularize)
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! Compute diagonal of the correlation part of the self-energy
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implicit none
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include 'parameters.h'
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! Input variables
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integer,intent(in) :: p
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double precision,intent(in) :: w
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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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logical,intent(in) :: regularize
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! Local variables
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integer :: i,a,jb
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double precision :: eps
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double precision :: Dpijb,Dpajb
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! Initialize
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SigmaC = 0d0
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if (regularize) then
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! Occupied part of the correlation self-energy
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do i=nC+1,nO
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do jb=1,nS
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eps = w - e(i) + Omega(jb)
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Dpijb = e(p) - e(i) + Omega(jb)
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SigmaC = SigmaC + 2d0*rho(p,i,jb)**2*(1d0-exp(-2d0*eta*Dpijb*Dpijb))/eps
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enddo
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enddo
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! Virtual part of the correlation self-energy
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do a=nO+1,nBas-nR
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do jb=1,nS
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eps = w - e(a) - Omega(jb)
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Dpajb = e(p) - e(a) - Omega(jb)
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SigmaC = SigmaC + 2d0*rho(p,a,jb)**2*(1d0-exp(-2d0*eta*Dpajb*Dpajb))/eps
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enddo
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enddo
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! We add the static SRG term in the self-energy directly
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! do i=nC+1,nO
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! do jb=1,nS
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! Dpijb = e(p) - e(i) + Omega(jb)
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! SigmaC = SigmaC + 2d0*rho(p,i,jb)**2*(exp(-2d0*eta*Dpijb*Dpijb)/Dpijb)
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! enddo
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! enddo
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! do a=nO+1,nBas-nR
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! do jb=1,nS
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! Dpajb = e(p) - e(a) - Omega(jb)
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! SigmaC = SigmaC + 2d0*rho(p,a,jb)**2*(exp(-2d0*eta*Dpajb*Dpajb)/Dpajb)
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! enddo
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! enddo
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else
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! Occupied part of the correlation self-energy
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do i=nC+1,nO
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do jb=1,nS
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eps = w - e(i) + Omega(jb)
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SigmaC = SigmaC + 2d0*rho(p,i,jb)**2*eps/(eps**2 + eta**2)
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enddo
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enddo
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! Virtual part of the correlation self-energy
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do a=nO+1,nBas-nR
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do jb=1,nS
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eps = w - e(a) - Omega(jb)
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SigmaC = SigmaC + 2d0*rho(p,a,jb)**2*eps/(eps**2 + eta**2)
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enddo
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enddo
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end if
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end function SigmaC
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