mirror of https://github.com/pfloos/quack
79 lines
2.2 KiB
Fortran
79 lines
2.2 KiB
Fortran
double precision function dSigmaC(x,w,eta,nBas,nC,nO,nV,nR,nS,e,Omega,rho,regularize)
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! Compute the derivative 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) :: x
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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,j,a,b,p,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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dSigmaC = 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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dSigmaC = dSigmaC - 2d0*rho(p,i,jb)**2*(1d0-exp(-2*eta*Dpijb*Dpijb))/(eps**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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Dpajb = e(p) - e(a) - Omega(jb)
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dSigmaC = dSigmaC - 2d0*rho(p,a,jb)**2*(1d0-exp(-2*eta*Dpajb*Dpajb))/(eps**2)
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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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jb = 0
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do j=nC+1,nO
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do b=nO+1,nBas-nR
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jb = jb + 1
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eps = w - e(i) + Omega(jb)
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dSigmaC = dSigmaC - 2d0*rho(x,i,jb)**2*(eps**2 - eta**2)/(eps**2 + eta**2)**2
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enddo
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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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jb = 0
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do j=nC+1,nO
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do b=nO+1,nBas-nR
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jb = jb + 1
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eps = w - e(a) - Omega(jb)
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dSigmaC = dSigmaC - 2d0*rho(x,a,jb)**2*(eps**2 - eta**2)/(eps**2 + eta**2)**2
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enddo
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enddo
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enddo
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end if
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end function dSigmaC
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