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mirror of https://github.com/pfloos/quack synced 2024-12-24 21:33:45 +01:00
QuAcK/src/MBPT/UG0W0.f90

243 lines
8.0 KiB
Fortran

subroutine UG0W0(doACFDT,exchange_kernel,doXBS,COHSEX,BSE,TDA_W,TDA,dBSE,dTDA,evDyn,spin_conserved,spin_flip, &
linearize,eta,nBas,nC,nO,nV,nR,nS,ENuc,EUHF,S,ERI,ERI_aaaa,ERI_aabb,ERI_bbbb, &
dipole_int_aa,dipole_int_bb,PHF,cHF,eHF,Vxc,eGW)
! Perform unrestricted G0W0 calculation
implicit none
include 'parameters.h'
include 'quadrature.h'
! Input variables
logical,intent(in) :: doACFDT
logical,intent(in) :: exchange_kernel
logical,intent(in) :: doXBS
logical,intent(in) :: COHSEX
logical,intent(in) :: BSE
logical,intent(in) :: TDA_W
logical,intent(in) :: TDA
logical,intent(in) :: dBSE
logical,intent(in) :: dTDA
logical,intent(in) :: evDyn
logical,intent(in) :: spin_conserved
logical,intent(in) :: spin_flip
logical,intent(in) :: linearize
double precision,intent(in) :: eta
integer,intent(in) :: nBas
integer,intent(in) :: nC(nspin)
integer,intent(in) :: nO(nspin)
integer,intent(in) :: nV(nspin)
integer,intent(in) :: nR(nspin)
integer,intent(in) :: nS(nspin)
double precision,intent(in) :: ENuc
double precision,intent(in) :: EUHF
double precision,intent(in) :: S(nBas,nBas)
double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
double precision,intent(in) :: ERI_aaaa(nBas,nBas,nBas,nBas)
double precision,intent(in) :: ERI_aabb(nBas,nBas,nBas,nBas)
double precision,intent(in) :: ERI_bbbb(nBas,nBas,nBas,nBas)
double precision,intent(in) :: dipole_int_aa(nBas,nBas,ncart)
double precision,intent(in) :: dipole_int_bb(nBas,nBas,ncart)
double precision,intent(in) :: eHF(nBas,nspin)
double precision,intent(in) :: cHF(nBas,nBas,nspin)
double precision,intent(in) :: PHF(nBas,nBas,nspin)
double precision,intent(in) :: Vxc(nBas,nspin)
! Local variables
logical :: print_W = .true.
integer :: is
integer :: ispin
double precision :: EcRPA
double precision :: EcGM(nspin)
double precision :: EcBSE(nspin)
double precision :: EcAC(nspin)
double precision,allocatable :: SigX(:,:)
double precision,allocatable :: SigC(:,:)
double precision,allocatable :: Z(:,:)
integer :: nS_aa,nS_bb,nS_sc
double precision,allocatable :: OmRPA(:)
double precision,allocatable :: XpY_RPA(:,:)
double precision,allocatable :: XmY_RPA(:,:)
double precision,allocatable :: rho_RPA(:,:,:,:)
double precision,allocatable :: eGWlin(:,:)
! Output variables
double precision :: eGW(nBas,nspin)
! Hello world
write(*,*)
write(*,*)'************************************************'
write(*,*)'| One-shot G0W0 calculation |'
write(*,*)'| *** Unrestricted version *** |'
write(*,*)'************************************************'
write(*,*)
! Initialization
EcRPA = 0d0
! COHSEX approximation
if(COHSEX) then
write(*,*) 'COHSEX approximation activated!'
write(*,*)
end if
! TDA for W
if(TDA_W) then
write(*,*) 'Tamm-Dancoff approximation for dynamic screening!'
write(*,*)
end if
! TDA
if(TDA) then
write(*,*) 'Tamm-Dancoff approximation activated!'
write(*,*)
end if
! Memory allocation
nS_aa = nS(1)
nS_bb = nS(2)
nS_sc = nS_aa + nS_bb
allocate(SigX(nBas,nspin),SigC(nBas,nspin),Z(nBas,nspin),eGWlin(nBas,nspin), &
OmRPA(nS_sc),XpY_RPA(nS_sc,nS_sc),XmY_RPA(nS_sc,nS_sc),rho_RPA(nBas,nBas,nS_sc,nspin))
!-------------------!
! Compute screening !
!-------------------!
! Spin-conserving transition
ispin = 1
call unrestricted_linear_response(ispin,.true.,TDA_W,.false.,eta,nBas,nC,nO,nV,nR,nS_aa,nS_bb,nS_sc,nS_sc,1d0, &
eHF,ERI_aaaa,ERI_aabb,ERI_bbbb,OmRPA,rho_RPA,EcRPA,OmRPA,XpY_RPA,XmY_RPA)
if(print_W) call print_excitation('RPA@UHF ',5,nS_sc,OmRPA)
!----------------------!
! Excitation densities !
!----------------------!
call unrestricted_excitation_density(nBas,nC,nO,nR,nS_aa,nS_bb,nS_sc,ERI_aaaa,ERI_aabb,ERI_bbbb,XpY_RPA,rho_RPA)
!---------------------!
! Compute self-energy !
!---------------------!
do is=1,nspin
call self_energy_exchange_diag(nBas,cHF(:,:,is),PHF(:,:,is),ERI,SigX(:,is))
end do
call unrestricted_self_energy_correlation_diag(eta,nBas,nC,nO,nV,nR,nS_sc,eHF,OmRPA,rho_RPA,SigC,EcGM)
!--------------------------------!
! Compute renormalization factor !
!--------------------------------!
call unrestricted_renormalization_factor(eta,nBas,nC,nO,nV,nR,nS_sc,eHF,OmRPA,rho_RPA,Z)
!-----------------------------------!
! Solve the quasi-particle equation !
!-----------------------------------!
eGWlin(:,:) = eHF(:,:) + Z(:,:)*(SigX(:,:) + SigC(:,:) - Vxc(:,:))
if(linearize) then
write(*,*) ' *** Quasiparticle energies obtained by linearization *** '
write(*,*)
eGW(:,:) = eGWlin(:,:)
else
! Find graphical solution of the QP equation
do is=1,nspin
call unrestricted_QP_graph(nBas,nC(is),nO(is),nV(is),nR(is),nS_sc,eta,eHF(:,is),SigX(:,is),Vxc(:,is), &
OmRPA,rho_RPA(:,:,:,is),eGWlin(:,is),eGW(:,is))
end do
end if
! Compute RPA correlation energy
call unrestricted_linear_response(ispin,.true.,TDA_W,.false.,eta,nBas,nC,nO,nV,nR,nS_aa,nS_bb,nS_sc,nS_sc,1d0, &
eGW,ERI_aaaa,ERI_aabb,ERI_bbbb,OmRPA,rho_RPA,EcRPA,OmRPA,XpY_RPA,XmY_RPA)
! Dump results
call print_UG0W0(nBas,nO,eHF,ENuc,EUHF,SigC,Z,eGW,EcRPA,EcGM)
! Free memory
deallocate(OmRPA,XpY_RPA,XmY_RPA,rho_RPA)
! Perform BSE calculation
if(BSE) then
call unrestricted_Bethe_Salpeter(TDA_W,TDA,dBSE,dTDA,evDyn,spin_conserved,spin_flip,eta,nBas,nC,nO,nV,nR,nS,S, &
ERI_aaaa,ERI_aabb,ERI_bbbb,dipole_int_aa,dipole_int_bb,cHF,eHF,eGW,EcBSE)
if(exchange_kernel) then
EcBSE(1) = 0.5d0*EcBSE(1)
EcBSE(2) = 1.5d0*EcBSE(1)
end if
write(*,*)
write(*,*)'-------------------------------------------------------------------------------'
write(*,'(2X,A50,F20.10)') 'Tr@BSE@UG0W0 correlation energy (spin-conserved) =',EcBSE(1)
write(*,'(2X,A50,F20.10)') 'Tr@BSE@UG0W0 correlation energy (spin-flip) =',EcBSE(2)
write(*,'(2X,A50,F20.10)') 'Tr@BSE@UG0W0 correlation energy =',EcBSE(1) + EcBSE(2)
write(*,'(2X,A50,F20.10)') 'Tr@BSE@UG0W0 total energy =',ENuc + EUHF + EcBSE(1) + EcBSE(2)
write(*,*)'-------------------------------------------------------------------------------'
write(*,*)
! Compute the BSE correlation energy via the adiabatic connection
if(doACFDT) then
write(*,*) '------------------------------------------------------'
write(*,*) 'Adiabatic connection version of BSE correlation energy'
write(*,*) '------------------------------------------------------'
write(*,*)
if(doXBS) then
write(*,*) '*** scaled screening version (XBS) ***'
write(*,*)
end if
call unrestricted_ACFDT(exchange_kernel,doXBS,.true.,TDA_W,TDA,BSE,spin_conserved,spin_flip,eta, &
nBas,nC,nO,nV,nR,nS,ERI_aaaa,ERI_aabb,ERI_bbbb,eHF,eGW,EcAC)
write(*,*)
write(*,*)'-------------------------------------------------------------------------------'
write(*,'(2X,A50,F20.10)') 'AC@BSE@UG0W0 correlation energy (spin-conserved) =',EcAC(1)
write(*,'(2X,A50,F20.10)') 'AC@BSE@UG0W0 correlation energy (spin-flip) =',EcAC(2)
write(*,'(2X,A50,F20.10)') 'AC@BSE@UG0W0 correlation energy =',EcAC(1) + EcAC(2)
write(*,'(2X,A50,F20.10)') 'AC@BSE@UG0W0 total energy =',ENuc + EUHF + EcAC(1) + EcAC(2)
write(*,*)'-------------------------------------------------------------------------------'
write(*,*)
end if
end if
end subroutine UG0W0