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quack/src/MBPT/Bethe_Salpeter_dynamic_perturbation.f90

129 lines
4.6 KiB
Fortran

subroutine Bethe_Salpeter_dynamic_perturbation(dTDA,eta,nBas,nC,nO,nV,nR,nS,eW,eGW,dipole_int,OmRPA,rho_RPA,OmBSE,XpY,XmY)
! Compute dynamical effects via perturbation theory for BSE
implicit none
include 'parameters.h'
! Input variables
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
double precision,intent(in) :: eW(nBas)
double precision,intent(in) :: eGW(nBas)
double precision,intent(in) :: dipole_int(nBas,nBas,ncart)
double precision,intent(in) :: OmRPA(nS)
double precision,intent(in) :: rho_RPA(nBas,nBas,nS)
double precision,intent(in) :: OmBSE(nS)
double precision,intent(in) :: XpY(nS,nS)
double precision,intent(in) :: XmY(nS,nS)
! Local variables
integer :: ia
integer,parameter :: maxS = 10
double precision :: gapGW
double precision,allocatable :: OmDyn(:)
double precision,allocatable :: ZDyn(:)
double precision,allocatable :: X(:)
double precision,allocatable :: Y(:)
double precision,allocatable :: Ap_dyn(:,:)
double precision,allocatable :: ZAp_dyn(:,:)
double precision,allocatable :: Bp_dyn(:,:)
double precision,allocatable :: ZBp_dyn(:,:)
double precision,allocatable :: Am_dyn(:,:)
double precision,allocatable :: ZAm_dyn(:,:)
double precision,allocatable :: Bm_dyn(:,:)
double precision,allocatable :: ZBm_dyn(:,:)
! Memory allocation
allocate(OmDyn(nS),ZDyn(nS),X(nS),Y(nS),Ap_dyn(nS,nS),ZAp_dyn(nS,nS))
if(.not.dTDA) allocate(Am_dyn(nS,nS),ZAm_dyn(nS,nS),Bp_dyn(nS,nS),ZBp_dyn(nS,nS),Bm_dyn(nS,nS),ZBm_dyn(nS,nS))
if(dTDA) then
write(*,*)
write(*,*) '*** dynamical TDA activated ***'
write(*,*)
end if
gapGW = eGW(nO+1) - eGW(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 GW gap = ',gapGW*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,:))
! First-order correction
if(dTDA) then
! Resonant part of the BSE correction for dynamical TDA
call Bethe_Salpeter_A_matrix_dynamic(eta,nBas,nC,nO,nV,nR,nS,1d0,eGW,OmRPA,rho_RPA,OmBSE(ia),Ap_dyn)
! Renormalization factor of the resonant parts for dynamical TDA
call Bethe_Salpeter_ZA_matrix_dynamic(eta,nBas,nC,nO,nV,nR,nS,1d0,eGW,OmRPA,rho_RPA,OmBSE(ia),ZAp_dyn)
ZDyn(ia) = dot_product(X,matmul(ZAp_dyn,X))
OmDyn(ia) = dot_product(X,matmul( Ap_dyn,X))
else
! Resonant and anti-resonant part of the BSE correction
call Bethe_Salpeter_AB_matrix_dynamic(eta,nBas,nC,nO,nV,nR,nS,1d0,eGW,OmRPA,rho_RPA,OmBSE(ia), &
Ap_dyn,Am_dyn,Bp_dyn,Bm_dyn)
! Renormalization factor of the resonant and anti-resonant parts
call Bethe_Salpeter_ZAB_matrix_dynamic(eta,nBas,nC,nO,nV,nR,nS,1d0,eGW,OmRPA,rho_RPA,OmBSE(ia), &
ZAp_dyn,ZAm_dyn,ZBp_dyn,ZBm_dyn)
ZDyn(ia) = dot_product(X,matmul(ZAp_dyn,X)) &
- dot_product(Y,matmul(ZAm_dyn,Y)) &
+ dot_product(X,matmul(ZBp_dyn,Y)) &
- dot_product(Y,matmul(ZBm_dyn,X))
OmDyn(ia) = dot_product(X,matmul(Ap_dyn,X)) &
- dot_product(Y,matmul(Am_dyn,Y)) &
+ dot_product(X,matmul(Bp_dyn,Y)) &
- dot_product(Y,matmul(Bm_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 Bethe_Salpeter_dynamic_perturbation