mirror of https://github.com/pfloos/quack
257 lines
7.4 KiB
Fortran
257 lines
7.4 KiB
Fortran
subroutine UGW_phBSE_dynamic_kernel_A(ispin,eta,nBas,nC,nO,nV,nR,nSa,nSb,nSt,nS_sc,lambda,eGW, &
|
|
ERI_aaaa,ERI_aabb,ERI_bbbb,OmRPA,rho_RPA,OmBSE,A_dyn,ZA_dyn)
|
|
|
|
! Compute the extra term for dynamical Bethe-Salpeter equation for linear response in the unrestricted formalism
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
integer,intent(in) :: ispin
|
|
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) :: nSa
|
|
integer,intent(in) :: nSb
|
|
integer,intent(in) :: nSt
|
|
integer,intent(in) :: nS_sc
|
|
double precision,intent(in) :: eta
|
|
double precision,intent(in) :: lambda
|
|
double precision,intent(in) :: eGW(nBas,nspin)
|
|
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) :: OmRPA(nS_sc)
|
|
double precision,intent(in) :: rho_RPA(nBas,nBas,nS_sc,nspin)
|
|
double precision,intent(in) :: OmBSE
|
|
|
|
! Local variables
|
|
|
|
double precision :: chi
|
|
double precision :: eps
|
|
integer :: i,j,a,b,ia,jb,kc
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: A_dyn(nSt,nSt)
|
|
double precision,intent(out) :: ZA_dyn(nSt,nSt)
|
|
|
|
!--------------------------------------------------!
|
|
! Build BSE matrix for spin-conserving transitions !
|
|
!--------------------------------------------------!
|
|
|
|
A_dyn(:,:) = 0d0
|
|
|
|
if(ispin == 1) then
|
|
|
|
! aaaa block
|
|
|
|
ia = 0
|
|
do i=nC(1)+1,nO(1)
|
|
do a=nO(1)+1,nBas-nR(1)
|
|
ia = ia + 1
|
|
jb = 0
|
|
do j=nC(1)+1,nO(1)
|
|
do b=nO(1)+1,nBas-nR(1)
|
|
jb = jb + 1
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,1)*OmRPA(kc)/(OmRPA(kc)**2 + eta**2)
|
|
end do
|
|
|
|
A_dyn(ia,jb) = A_dyn(ia,jb) - 2d0*lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,1) - eGW(j,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,1)*eps/(eps**2 + eta**2)
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,1) - eGW(i,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,1)*eps/(eps**2 + eta**2)
|
|
|
|
end do
|
|
|
|
A_dyn(ia,jb) = A_dyn(ia,jb) - lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,1) - eGW(j,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,1)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,1) - eGW(i,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,1)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
end do
|
|
|
|
ZA_dyn(ia,jb) = ZA_dyn(ia,jb) + lambda*chi
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
! bbbb block
|
|
|
|
ia = 0
|
|
do i=nC(2)+1,nO(2)
|
|
do a=nO(2)+1,nBas-nR(2)
|
|
ia = ia + 1
|
|
jb = 0
|
|
do j=nC(2)+1,nO(2)
|
|
do b=nO(2)+1,nBas-nR(2)
|
|
jb = jb + 1
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,2)*OmRPA(kc)/(OmRPA(kc)**2 + eta**2)
|
|
end do
|
|
|
|
A_dyn(nSa+ia,nSa+jb) = A_dyn(nSa+ia,nSa+jb) - 2d0*lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,2) - eGW(j,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,2)*eps/(eps**2 + eta**2)
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,2) - eGW(i,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,2)*eps/(eps**2 + eta**2)
|
|
|
|
end do
|
|
|
|
A_dyn(nSa+ia,nSa+jb) = A_dyn(nSa+ia,nSa+jb) - lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,2) - eGW(j,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,2)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,2) - eGW(i,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,2)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
end do
|
|
|
|
ZA_dyn(nSa+ia,nSa+jb) = ZA_dyn(nSa+ia,nSa+jb) + lambda*chi
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
!--------------------------------------------!
|
|
! Build BSE matrix for spin-flip transitions !
|
|
!--------------------------------------------!
|
|
|
|
if(ispin == 2) then
|
|
|
|
! abab block
|
|
|
|
ia = 0
|
|
do i=nC(1)+1,nO(1)
|
|
do a=nO(2)+1,nBas-nR(2)
|
|
ia = ia + 1
|
|
jb = 0
|
|
do j=nC(1)+1,nO(1)
|
|
do b=nO(2)+1,nBas-nR(2)
|
|
jb = jb + 1
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,2)*OmRPA(kc)/(OmRPA(kc)**2 + eta**2)
|
|
end do
|
|
|
|
A_dyn(ia,jb) = A_dyn(ia,jb) - 2d0*lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,2) - eGW(j,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,2)*eps/(eps**2 + eta**2)
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,2) - eGW(i,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,2)*eps/(eps**2 + eta**2)
|
|
|
|
end do
|
|
|
|
A_dyn(ia,jb) = A_dyn(ia,jb) - lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,2) - eGW(j,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,2)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,2) - eGW(i,1))
|
|
chi = chi + rho_RPA(i,j,kc,1)*rho_RPA(a,b,kc,2)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
end do
|
|
|
|
ZA_dyn(ia,jb) = ZA_dyn(ia,jb) + lambda*chi
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
! baba block
|
|
|
|
ia = 0
|
|
do i=nC(2)+1,nO(2)
|
|
do a=nO(1)+1,nBas-nR(1)
|
|
ia = ia + 1
|
|
jb = 0
|
|
do j=nC(2)+1,nO(2)
|
|
do b=nO(1)+1,nBas-nR(1)
|
|
jb = jb + 1
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,1)*OmRPA(kc)/(OmRPA(kc)**2 + eta**2)
|
|
end do
|
|
|
|
A_dyn(nSa+ia,nSa+jb) = A_dyn(nSa+ia,nSa+jb) - 2d0*lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,1) - eGW(j,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,1)*eps/(eps**2 + eta**2)
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,1) - eGW(i,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,1)*eps/(eps**2 + eta**2)
|
|
|
|
end do
|
|
|
|
A_dyn(nSa+ia,nSa+jb) = A_dyn(nSa+ia,nSa+jb) - lambda*chi
|
|
|
|
chi = 0d0
|
|
do kc=1,nS_sc
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(a,1) - eGW(j,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,1)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
eps = + OmBSE - OmRPA(kc) - (eGW(b,1) - eGW(i,2))
|
|
chi = chi + rho_RPA(i,j,kc,2)*rho_RPA(a,b,kc,1)*(eps**2 - eta**2)/(eps**2 + eta**2)**2
|
|
|
|
end do
|
|
|
|
ZA_dyn(nSa+ia,nSa+jb) = ZA_dyn(nSa+ia,nSa+jb) + lambda*chi
|
|
|
|
end do
|
|
end do
|
|
end do
|
|
end do
|
|
|
|
end if
|
|
|
|
end subroutine
|