10
1
mirror of https://github.com/pfloos/quack synced 2025-05-06 07:05:33 +02:00
QuAcK/src/GF/complex_cRGF2_self_energy.f90
2025-04-24 20:23:59 +02:00

125 lines
3.9 KiB
Fortran

subroutine complex_cRGF2_self_energy(eta,nBas,nC,nO,nV,nR,e,ERI,SigC,Z)
! Compute diagonal part of the GF2 self-energy and its renormalization factor
implicit none
include 'parameters.h'
! Input variables
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
complex*16,intent(in) :: e(nBas)
complex*16,intent(in) :: ERI(nBas,nBas,nBas,nBas)
! Local variables
integer :: i,j,a,b
integer :: p,q
double precision :: eps
double precision :: eta_tilde
complex*16 :: num
double precision,allocatable :: Re_DS(:)
double precision,allocatable :: Im_DS(:)
complex*16 :: z_dummy
double precision,allocatable :: Re_SigC(:,:)
double precision,allocatable :: Im_SigC(:,:)
double precision,allocatable :: Re_Z(:)
double precision,allocatable :: Im_Z(:)
! Output variables
complex*16,intent(out) :: SigC(nBas,nBas)
complex*16,intent(out) :: Z(nBas)
! Initialize
allocate(Re_DS(nBas),Im_DS(nBas),Re_SigC(nBas,nBas),Im_SigC(nBas,nBas),&
Re_Z(nBas),Im_Z(nBas))
Re_SigC(:,:) = 0d0
Im_SigC(:,:) = 0d0
Re_DS(:) = 0d0
Im_DS(:) = 0d0
! Compute GF2 self-energy
!$OMP PARALLEL &
!$OMP SHARED(Re_DS,Im_DS,Im_SigC,Re_SigC,ERI,eta,nC,nO,nBas,nR,e) &
!$OMP PRIVATE(p,i,j,a,eps,num,eta_tilde,z_dummy) &
!$OMP DEFAULT(NONE)
!$OMP DO
do p=nC+1,nBas-nR
do q=nC+1,nBas-nR
do i=nC+1,nO
do j=nC+1,nO
do a=nO+1,nBas-nR
eps = real(e(p)) + real(e(a)) - real(e(i)) - real(e(j))
eta_tilde = eta - aimag(e(p)) + aimag(e(i)) - (aimag(e(a)) - aimag(e(j)))
num = (2d0*ERI(p,a,i,j) - ERI(p,a,j,i))*ERI(q,a,i,j)
z_dummy = num*cmplx(eps/(eps**2 + eta_tilde**2),eta_tilde/(eps**2 + eta_tilde**2),kind=8)
Re_SigC(p,q) = Re_SigC(p,q) + real(z_dummy)
Im_SigC(p,q) = Im_SigC(p,q) + aimag(z_dummy)
if(p==q) then
z_dummy = num*cmplx(-(eps**2 - eta_tilde**2)/(eps**2 + eta_tilde**2)**2,&
-2*eta_tilde*eps/(eps**2 + eta_tilde**2)**2,kind=8)
Re_DS(p) = Re_DS(p) + real(z_dummy)
Im_DS(p) = Im_DS(p) + aimag(z_dummy)
end if
end do
end do
end do
end do
end do
!$OMP END DO
!$OMP END PARALLEL
!$OMP PARALLEL &
!$OMP SHARED(Re_DS,Im_DS,Re_SigC,Im_SigC,ERI,eta,nC,nO,nBas,nR,e) &
!$OMP PRIVATE(p,i,a,b,eps,num,eta_tilde,z_dummy) &
!$OMP DEFAULT(NONE)
!$OMP DO
do p=nC+1,nBas-nR
do q=nC+1,nBas-nR
do i=nC+1,nO
do a=nO+1,nBas-nR
do b=nO+1,nBas-nR
eps = real(e(p)) + real(e(i)) - real(e(a)) - real(e(b))
eta_tilde = eta + aimag(e(p)) - aimag(e(a)) - aimag(e(b)) + aimag(e(i))
num = (2d0*ERI(p,i,a,b) - ERI(p,i,b,a))*ERI(q,i,a,b)
z_dummy = num*cmplx(eps/(eps**2 + eta_tilde**2),-eta_tilde/(eps**2 + eta_tilde**2),kind=8)
Re_SigC(p,q) = Re_SigC(p,q) + real(z_dummy)
Im_SigC(p,q) = Im_SigC(p,q) + aimag(z_dummy)
if(p==q) then
z_dummy = num*cmplx(-(eps**2 - eta_tilde**2)/(eps**2 + eta_tilde**2)**2,&
2*eta_tilde*eps/(eps**2 + eta_tilde**2)**2,kind=8)
Re_DS(p) = Re_DS(p) + real(z_dummy)
Im_DS(p) = Im_DS(p) + aimag(z_dummy)
end if
end do
end do
end do
end do
end do
!$OMP END DO
!$OMP END PARALLEL
Re_Z(:) = (1d0-Re_DS(:))/((1d0 - Re_DS(:))**2 + Im_DS(:)**2)
Im_Z(:) = Im_DS(:)/((1d0 - Re_DS(:))**2 + Im_DS(:)**2)
Z = cmplx(Re_Z,Im_Z,kind=8)
SigC = cmplx(Re_SigC,Im_SigC,kind=8)
deallocate(Re_DS,Im_DS,Re_Z,Im_Z,Re_SigC,Im_SigC)
end subroutine