mirror of
https://github.com/pfloos/quack
synced 2024-06-20 04:02:18 +02:00
77 lines
1.7 KiB
Fortran
77 lines
1.7 KiB
Fortran
subroutine QP_graph_GF2(eta,nBas,nC,nO,nV,nR,nS,eHF,eGF2lin,ERI,eGF2)
|
|
|
|
! Compute the graphical solution of the GF2 QP equation
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
double precision,intent(in) :: eta
|
|
integer,intent(in) :: nBas,nC,nO,nV,nR,nS
|
|
double precision,intent(in) :: eHF(nBas)
|
|
double precision,intent(in) :: eGF2lin(nBas)
|
|
double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
|
|
|
|
! Local variables
|
|
|
|
integer :: p
|
|
integer :: nIt
|
|
integer,parameter :: maxIt = 64
|
|
double precision,parameter :: thresh = 1d-6
|
|
double precision,external :: SigmaC_GF2,dSigmaC_GF2
|
|
double precision :: sigC,dsigC
|
|
double precision :: f,df
|
|
double precision :: w
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: eGF2(nBas)
|
|
|
|
|
|
! Run Newton's algorithm to find the root
|
|
|
|
do p=nC+1,nBas-nR
|
|
|
|
write(*,*) '-----------------'
|
|
write(*,'(A10,I3)') 'Orbital ',p
|
|
write(*,*) '-----------------'
|
|
|
|
w = eGF2lin(p)
|
|
nIt = 0
|
|
f = 1d0
|
|
write(*,'(A3,I3,A1,1X,3F15.9)') 'It.',nIt,':',w*HaToeV,f
|
|
|
|
do while (abs(f) > thresh .and. nIt < maxIt)
|
|
|
|
nIt = nIt + 1
|
|
|
|
sigC = SigmaC_GF2(p,w,eta,nBas,nC,nO,nV,nR,nS,eHF,ERI)
|
|
dsigC = dSigmaC_GF2(p,w,eta,nBas,nC,nO,nV,nR,nS,eHF,ERI)
|
|
f = w - eHF(p) - sigC
|
|
df = 1d0 - dsigC
|
|
|
|
w = w - f/df
|
|
|
|
write(*,'(A3,I3,A1,1X,3F15.9)') 'It.',nIt,':',w*HaToeV,f,sigC
|
|
|
|
|
|
end do
|
|
|
|
if(nIt == maxIt) then
|
|
|
|
write(*,*) 'Newton root search has not converged!'
|
|
|
|
else
|
|
|
|
eGF2(p) = w
|
|
|
|
write(*,'(A32,F16.10)') 'Quasiparticle energy (eV) ',eGF2(p)*HaToeV
|
|
write(*,*)
|
|
|
|
end if
|
|
|
|
end do
|
|
|
|
end subroutine QP_graph_GF2
|