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https://github.com/pfloos/quack
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86 lines
2.5 KiB
Fortran
86 lines
2.5 KiB
Fortran
subroutine BSE2(TDA,singlet_manifold,triplet_manifold,eta,nBas,nC,nO,nV,nR,nS,ERI,eHF,eGF,EcBSE)
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! Compute the Bethe-Salpeter excitation energies
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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) :: TDA
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logical,intent(in) :: singlet_manifold
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logical,intent(in) :: triplet_manifold
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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) :: eHF(nBas)
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double precision,intent(in) :: eGF(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 :: ispin
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double precision,allocatable :: OmBSE(:,:)
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double precision,allocatable :: XpY(:,:,:)
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double precision,allocatable :: XmY(:,:,:)
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double precision :: rho
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! Output variables
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double precision,intent(out) :: EcBSE(nspin)
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! Memory allocation
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allocate(OmBSE(nS,nspin),XpY(nS,nS,nspin),XmY(nS,nS,nspin))
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!-------------------
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! Singlet manifold
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!-------------------
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if(singlet_manifold) then
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ispin = 1
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EcBSE(ispin) = 0d0
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! Compute BSE2 excitation energies
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call linear_response(ispin,.false.,TDA,.false.,eta,nBas,nC,nO,nV,nR,nS,1d0,eGF(:),ERI(:,:,:,:), &
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rho,EcBSE(ispin),OmBSE(:,ispin),XpY(:,:,ispin),XmY(:,:,ispin))
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call print_excitation('BSE2 ',ispin,nS,OmBSE(:,ispin))
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! Compute dynamic correction for BSE via perturbation theory
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call BSE2_dynamic_perturbation(ispin,eta,nBas,nC,nO,nV,nR,nS, &
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ERI(:,:,:,:),eHF(:),eGF(:),OmBSE(:,ispin),XpY(:,:,ispin),XmY(:,:,ispin))
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end if
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!-------------------
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! Triplet manifold
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!-------------------
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if(triplet_manifold) then
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ispin = 2
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EcBSE(ispin) = 0d0
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! Compute BSE2 excitation energies
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call linear_response(ispin,.false.,TDA,.false.,eta,nBas,nC,nO,nV,nR,nS,1d0,eGF(:),ERI(:,:,:,:), &
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rho,EcBSE(ispin),OmBSE(:,ispin),XpY(:,:,ispin),XmY(:,:,ispin))
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call print_excitation('BSE2 ',ispin,nS,OmBSE(:,ispin))
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! Compute dynamic correction for BSE via perturbation theory
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call BSE2_dynamic_perturbation(ispin,eta,nBas,nC,nO,nV,nR,nS, &
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ERI(:,:,:,:),eHF(:),eGF(:),OmBSE(:,ispin),XpY(:,:,ispin),XmY(:,:,ispin))
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end if
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end subroutine BSE2
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