mirror of https://github.com/pfloos/quack
151 lines
3.9 KiB
Fortran
151 lines
3.9 KiB
Fortran
subroutine USRG_self_energy(eta,nBas,nC,nO,nV,nR,nS,e,Om,rho,EcGM,SigC,Z)
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! Compute 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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double precision,intent(in) :: eta
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integer,intent(in) :: nBas
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integer,intent(in) :: nC(nspin)
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integer,intent(in) :: nO(nspin)
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integer,intent(in) :: nV(nspin)
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integer,intent(in) :: nR(nspin)
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integer,intent(in) :: nS
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double precision,intent(in) :: e(nBas,nspin)
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double precision,intent(in) :: Om(nS)
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double precision,intent(in) :: rho(nBas,nBas,nS,nspin)
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! Local variables
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integer :: ispin
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integer :: i,j,a,b
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integer :: p,q,r
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integer :: m
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double precision :: Dpim,Dqim,Dpam,Dqam,Diam
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double precision :: t1,t2
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! Output variables
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double precision,intent(out) :: EcGM
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double precision,intent(out) :: SigC(nBas,nBas,nspin)
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double precision,intent(out) :: Z(nBas,nspin)
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! Initialize
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SigC(:,:,:) = 0d0
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!--------------------!
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! SRG-GW self-energy !
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!--------------------!
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! Occupied part of the correlation self-energy
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call wall_time(t1)
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!$OMP PARALLEL &
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!$OMP SHARED(SigC,rho,eta,nS,nC,nO,nBas,nR,e,Om) &
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!$OMP PRIVATE(ispin,m,i,q,p,Dpim,Dqim) &
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!$OMP DEFAULT(NONE)
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!$OMP DO
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do ispin=1,nspin
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do q=nC(ispin)+1,nBas-nR(ispin)
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do p=nC(ispin)+1,nBas-nR(ispin)
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do m=1,nS
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do i=nC(ispin)+1,nO(ispin)
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Dpim = e(p,ispin) - e(i,ispin) + Om(m)
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Dqim = e(q,ispin) - e(i,ispin) + Om(m)
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SigC(p,q,ispin) = SigC(p,q,ispin) &
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+ rho(p,i,m,ispin)*rho(q,i,m,ispin)*(1d0-dexp(-eta*Dpim*Dpim)*dexp(-eta*Dqim*Dqim)) &
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*(Dpim + Dqim)/(Dpim*Dpim + Dqim*Dqim)
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end do
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end do
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end do
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end do
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end do
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!$OMP END DO
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!$OMP END PARALLEL
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call wall_time(t2)
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print *, "first loop", (t2-t1)
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! Virtual part of the correlation self-energy
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call wall_time(t1)
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!$OMP PARALLEL &
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!$OMP SHARED(SigC,rho,eta,nS,nC,nO,nR,nBas,e,Om) &
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!$OMP PRIVATE(ispin,m,a,q,p,Dpam,Dqam) &
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!$OMP DEFAULT(NONE)
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!$OMP DO
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do ispin=1,nspin
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do q=nC(ispin)+1,nBas-nR(ispin)
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do p=nC(ispin)+1,nBas-nR(ispin)
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do m=1,nS
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do a=nO(ispin)+1,nBas-nR(ispin)
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Dpam = e(p,ispin) - e(a,ispin) - Om(m)
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Dqam = e(q,ispin) - e(a,ispin) - Om(m)
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SigC(p,q,ispin) = SigC(p,q,ispin) &
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+ rho(p,a,m,ispin)*rho(q,a,m,ispin)*(1d0-exp(-eta*Dpam*Dpam)*exp(-eta*Dqam*Dqam)) &
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*(Dpam + Dqam)/(Dpam*Dpam + Dqam*Dqam)
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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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!$OMP END DO
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!$OMP END PARALLEL
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call wall_time(t2)
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print *, "second loop", (t2-t1)
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! Initialize
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Z(:,:) = 0d0
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do ispin=1,nspin
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do p=nC(ispin)+1,nBas-nR(ispin)
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do i=nC(ispin)+1,nO(ispin)
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do m=1,nS
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Dpim = e(p,ispin) - e(i,ispin) + Om(m)
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Z(p,ispin) = Z(p,ispin) - rho(p,i,m,ispin)**2*(1d0-dexp(-2d0*eta*Dpim*Dpim))/Dpim**2
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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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! Virtual part of the correlation self-energy
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do ispin=1,nspin
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do p=nC(ispin)+1,nBas-nR(ispin)
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do a=nO(ispin)+1,nBas-nR(ispin)
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do m=1,nS
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Dpam = e(p,ispin) - e(a,ispin) - Om(m)
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Z(p,ispin) = Z(p,ispin) - rho(p,a,m,ispin)**2*(1d0-dexp(-2d0*eta*Dpam*Dpam))/Dpam**2
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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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! Compute renormalization factor from derivative of SigC
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Z(:,:) = 1d0/(1d0 - Z(:,:))
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! Galitskii-Migdal correlation energy
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EcGM = 0d0
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do ispin=1,nspin
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do i=nC(ispin)+1,nO(ispin)
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do a=nO(ispin)+1,nBas-nR(ispin)
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do m=1,nS
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Diam = e(a,ispin) - e(i,ispin) + Om(m)
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EcGM = EcGM - rho(a,i,m,ispin)*rho(a,i,m,ispin)*(1d0-exp(-2d0*eta*Diam*Diam))/Diam
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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 subroutine
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