subroutine G0F2(BSE,TDA,dBSE,dTDA,evDyn,singlet,triplet,linearize,eta,nBas,nC,nO,nV,nR,nS,ENuc,ERHF,ERI,dipole_int,eHF) ! Perform a one-shot second-order Green function calculation implicit none include 'parameters.h' ! Input variables logical,intent(in) :: BSE logical,intent(in) :: TDA logical,intent(in) :: dBSE logical,intent(in) :: dTDA logical,intent(in) :: evDyn logical,intent(in) :: singlet logical,intent(in) :: triplet logical,intent(in) :: linearize double precision,intent(in) :: eta integer,intent(in) :: nBas integer,intent(in) :: nO integer,intent(in) :: nC integer,intent(in) :: nV integer,intent(in) :: nR integer,intent(in) :: nS double precision,intent(in) :: ENuc double precision,intent(in) :: ERHF double precision,intent(in) :: eHF(nBas) double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas) double precision,intent(in) :: dipole_int(nBas,nBas,ncart) ! Local variables double precision :: eps double precision :: V double precision :: EcBSE(nspin) double precision,allocatable :: eGF2(:) double precision,allocatable :: Sig(:) double precision,allocatable :: Z(:) integer :: i,j,a,b,p ! Hello world write(*,*) write(*,*)'************************************************' write(*,*)'| One-shot second-order Green function |' write(*,*)'************************************************' write(*,*) ! Memory allocation allocate(Sig(nBas),Z(nBas),eGF2(nBas)) if(linearize) then write(*,*) '*** Quasiparticle equation will be linearized ***' write(*,*) end if ! Frequency-dependent second-order contribution Sig(:) = 0d0 Z(:) = 0d0 do p=nC+1,nBas-nR do i=nC+1,nO do j=nC+1,nO do a=nO+1,nBas-nR eps = eHF(p) + eHF(a) - eHF(i) - eHF(j) V = (2d0*ERI(p,a,i,j) - ERI(p,a,j,i))*ERI(p,a,i,j) Sig(p) = Sig(p) + V*eps/(eps**2 + eta**2) Z(p) = Z(p) - V*(eps**2 - eta**2)/(eps**2 + eta**2)**2 end do end do end do end do do p=nC+1,nBas-nR do i=nC+1,nO do a=nO+1,nBas-nR do b=nO+1,nBas-nR eps = eHF(p) + eHF(i) - eHF(a) - eHF(b) V = (2d0*ERI(p,i,a,b) - ERI(p,i,b,a))*ERI(p,i,a,b) Sig(p) = Sig(p) + V*eps/(eps**2 + eta**2) Z(p) = Z(p) - V*(eps**2 - eta**2)/(eps**2 + eta**2)**2 end do end do end do end do Z(:) = 1d0/(1d0 - Z(:)) if(linearize) then eGF2(:) = eHF(:) + Z(:)*Sig(:) else eGF2(:) = eHF(:) + Sig(:) end if ! Print results call print_G0F2(nBas,nO,eHF,Sig,eGF2,Z) ! Perform BSE2 calculation if(BSE) then call BSE2(TDA,dBSE,dTDA,evDyn,singlet,triplet,eta,nBas,nC,nO,nV,nR,nS,ERI,dipole_int,eHF,eGF2,EcBSE) end if end subroutine G0F2