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mirror of https://github.com/pfloos/quack synced 2024-06-02 03:15:31 +02:00
quack/src/GT/Bethe_Salpeter_Tmatrix_dynamic_perturbation.f90
Pierre-Francois Loos 16431bcd33 ufG0W0
2022-01-17 08:02:11 +01:00

136 lines
4.8 KiB
Fortran

subroutine Bethe_Salpeter_Tmatrix_dynamic_perturbation(ispin,dTDA,eta,nBas,nC,nO,nV,nR,nS,nOOs,nVVs,nOOt,nVVt, &
Omega1s,Omega2s,Omega1t,Omega2t,rho1s,rho2s,rho1t,rho2t,eT,eGT, &
dipole_int,OmBSE,XpY,XmY,TAs,TBs,TAt,TBt)
! Compute dynamical effects via perturbation theory for BSE@GT
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: ispin
logical,intent(in) :: dTDA
double precision,intent(in) :: eta
integer,intent(in) :: nBas
integer,intent(in) :: nC
integer,intent(in) :: nO
integer,intent(in) :: nV
integer,intent(in) :: nR
integer,intent(in) :: nS
integer,intent(in) :: nOOs
integer,intent(in) :: nVVs
integer,intent(in) :: nOOt
integer,intent(in) :: nVVt
double precision,intent(in) :: eT(nBas)
double precision,intent(in) :: eGT(nBas)
double precision,intent(in) :: dipole_int(nBas,nBas,ncart)
double precision,intent(in) :: OmBSE(nS)
double precision,intent(in) :: XpY(nS,nS)
double precision,intent(in) :: XmY(nS,nS)
double precision,intent(in) :: Omega1s(nVVs)
double precision,intent(in) :: Omega2s(nOOs)
double precision,intent(in) :: rho1s(nBas,nBas,nVVs)
double precision,intent(in) :: rho2s(nBas,nBas,nOOs)
double precision,intent(in) :: Omega1t(nVVt)
double precision,intent(in) :: Omega2t(nOOt)
double precision,intent(in) :: rho1t(nBas,nBas,nVVt)
double precision,intent(in) :: rho2t(nBas,nBas,nOOt)
double precision,intent(in) :: TAs(nS,nS)
double precision,intent(in) :: TBs(nS,nS)
double precision,intent(in) :: TAt(nS,nS)
double precision,intent(in) :: TBt(nS,nS)
! Local variables
integer :: ia
integer :: maxS = 10
double precision :: gapGT
double precision,allocatable :: OmDyn(:)
double precision,allocatable :: ZDyn(:)
double precision,allocatable :: X(:)
double precision,allocatable :: Y(:)
double precision,allocatable :: dTAs(:,:)
double precision,allocatable :: ZAs(:,:)
double precision,allocatable :: dTAt(:,:)
double precision,allocatable :: ZAt(:,:)
! Memory allocation
maxS = min(nS,maxS)
allocate(OmDyn(maxS),ZDyn(maxS),X(nS),Y(nS),dTAs(nS,nS),ZAs(nS,nS),dTAt(nS,nS),ZAt(nS,nS))
if(dTDA) then
write(*,*)
write(*,*) '*** dynamical TDA activated ***'
write(*,*)
else
print*, ' Beyond-TDA dynamical correction for BSE@GT NYI'
return
end if
OmDyn(:) = 0d0
ZDyn(:) = 0d0
do ia=1,maxS
! Compute dynamical T-matrix for alpha-beta block
call dynamic_Tmatrix_A(eta,nBas,nC,nO,nV,nR,nS,nOOs,nVVs,1d0,eGT,Omega1s,Omega2s,rho1s,rho2s,OmBSE(ia),dTAs,ZAs)
! Compute dynamical T-matrix for alpha-beta block
call dynamic_Tmatrix_A(eta,nBas,nC,nO,nV,nR,nS,nOOt,nVVt,1d0,eGT,Omega1t,Omega2t,rho1t,rho2t,OmBSE(ia),dTAt,ZAt)
X(:) = 0.5d0*(XpY(ia,:) + XmY(ia,:))
Y(:) = 0.5d0*(XpY(ia,:) - XmY(ia,:))
! First-order correction
if(ispin == 1) then
ZDyn(ia) = dot_product(X,matmul(ZAt+ZAs,X))
OmDyn(ia) = dot_product(X,matmul(dTAt+dTAs,X)) - dot_product(X,matmul(TAt+TAs,X))
end if
if(ispin == 2) then
ZDyn(ia) = dot_product(X,matmul(ZAt-ZAs,X))
OmDyn(ia) = dot_product(X,matmul(dTAt-dTAs,X)) - dot_product(X,matmul(TAt-TAs,X))
end if
ZDyn(ia) = 1d0/(1d0 - ZDyn(ia))
OmDyn(ia) = ZDyn(ia)*OmDyn(ia)
end do
!--------------!
! Dump results !
!--------------!
gapGT = eGT(nO+1) - eGT(nO)
write(*,*) '---------------------------------------------------------------------------------------------------'
write(*,*) ' First-order dynamical correction to static Bethe-Salpeter excitation energies '
write(*,*) '---------------------------------------------------------------------------------------------------'
write(*,'(A57,F10.6,A3)') ' BSE neutral excitation must be lower than the GT gap = ',gapGT*HaToeV,' eV'
write(*,*) '---------------------------------------------------------------------------------------------------'
write(*,'(2X,A5,1X,A20,1X,A20,1X,A20,1X,A20)') '#','Static (eV)','Dynamic (eV)','Correction (eV)','Renorm. (eV)'
write(*,*) '---------------------------------------------------------------------------------------------------'
do ia=1,maxS
write(*,'(2X,I5,5X,F15.6,5X,F15.6,5X,F15.6,5X,F15.6)') &
ia,OmBSE(ia)*HaToeV,(OmBSE(ia)+OmDyn(ia))*HaToeV,OmDyn(ia)*HaToeV,ZDyn(ia)
end do
write(*,*) '---------------------------------------------------------------------------------------------------'
write(*,*)
end subroutine Bethe_Salpeter_Tmatrix_dynamic_perturbation