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quack/src/QuAcK/BSE2_dynamic_perturbation.f90
2020-06-04 13:08:31 +02:00

107 lines
3.9 KiB
Fortran

subroutine BSE2_dynamic_perturbation(ispin,eta,nBas,nC,nO,nV,nR,nS,ERI,eHF,eGF,OmBSE,XpY,XmY)
! Compute dynamical effects via perturbation theory for BSE
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: ispin
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
double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
double precision,intent(in) :: eHF(nBas)
double precision,intent(in) :: eGF(nBas)
double precision,intent(in) :: OmBSE(nS)
double precision,intent(in) :: XpY(nS,nS)
double precision,intent(in) :: XmY(nS,nS)
! Local variables
logical :: dTDA = .true.
integer :: ia
integer,parameter :: maxS = 10
double precision :: gapGF
double precision,allocatable :: OmDyn(:)
double precision,allocatable :: ZDyn(:)
double precision,allocatable :: X(:)
double precision,allocatable :: Y(:)
double precision,allocatable :: A_dyn(:,:)
double precision,allocatable :: ZA_dyn(:,:)
double precision,allocatable :: B_dyn(:,:)
double precision,allocatable :: ZB_dyn(:,:)
! Memory allocation
allocate(OmDyn(nS),ZDyn(nS),X(nS),Y(nS),A_dyn(nS,nS),ZA_dyn(nS,nS))
if(.not.dTDA) allocate(B_dyn(nS,nS),ZB_dyn(nS,nS))
! Print main components of transition vectors
call print_transition_vectors(nBas,nC,nO,nV,nR,nS,OmBSE,XpY,XmY)
gapGF = eGF(nO+1) - eGF(nO)
write(*,*) '---------------------------------------------------------------------------------------------------'
write(*,*) ' First-order dynamical correction to static 2nd-order Bethe-Salpeter excitation energies '
write(*,*) '---------------------------------------------------------------------------------------------------'
write(*,'(A58,F10.6,A3)') ' BSE neutral excitation must be lower than the GF2 gap = ',gapGF*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,min(nS,maxS)
X(:) = 0.5d0*(XpY(ia,:) + XmY(ia,:))
Y(:) = 0.5d0*(XpY(ia,:) - XmY(ia,:))
! Resonant part of the BSE correction for dynamical TDA
call BSE2_A_matrix_dynamic(ispin,eta,nBas,nC,nO,nV,nR,nS,1d0,ERI(:,:,:,:),eGF(:),OmBSE(ia),A_dyn(:,:),ZA_dyn(:,:))
if(dTDA) then
ZDyn(ia) = dot_product(X(:),matmul(ZA_dyn(:,:),X(:)))
OmDyn(ia) = dot_product(X(:),matmul(A_dyn(:,:),X(:)))
else
! Anti-resonant part of the BSE correction (frequency independent)
call BSE2_B_matrix_dynamic(ispin,eta,nBas,nC,nO,nV,nR,nS,1d0,ERI(:,:,:,:),eGF(:),B_dyn(:,:),ZB_dyn(:,:))
ZDyn(ia) = dot_product(X(:),matmul(ZA_dyn(:,:),X(:))) &
- dot_product(Y(:),matmul(ZA_dyn(:,:),Y(:))) &
+ dot_product(X(:),matmul(ZB_dyn(:,:),Y(:))) &
- dot_product(Y(:),matmul(ZB_dyn(:,:),X(:)))
OmDyn(ia) = dot_product(X(:),matmul(A_dyn(:,:),X(:))) &
- dot_product(Y(:),matmul(A_dyn(:,:),Y(:))) &
+ dot_product(X(:),matmul(B_dyn(:,:),Y(:))) &
- dot_product(Y(:),matmul(B_dyn(:,:),X(:)))
end if
ZDyn(ia) = 1d0/(1d0 - ZDyn(ia))
OmDyn(ia) = ZDyn(ia)*OmDyn(ia)
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 BSE2_dynamic_perturbation