mirror of https://github.com/pfloos/quack
86 lines
2.1 KiB
Fortran
86 lines
2.1 KiB
Fortran
subroutine QP_graph(nBas,nC,nO,nV,nR,nS,eta,eHF,SigX,Vxc,Omega,rho,eGWlin,eGW,regularize)
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! Compute the graphical solution of the QP equation
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implicit none
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include 'parameters.h'
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! Input variables
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integer,intent(in) :: nBas
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integer,intent(in) :: nC
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integer,intent(in) :: nO
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integer,intent(in) :: nV
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integer,intent(in) :: nR
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integer,intent(in) :: nS
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double precision,intent(in) :: eta
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double precision,intent(in) :: eHF(nBas)
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double precision,intent(in) :: SigX(nBas)
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double precision,intent(in) :: Vxc(nBas)
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double precision,intent(in) :: Omega(nS)
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double precision,intent(in) :: rho(nBas,nBas,nS)
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double precision,intent(in) :: eGWlin(nBas)
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logical,intent(in) :: regularize
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! Local variables
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integer :: p
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integer :: nIt
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integer,parameter :: maxIt = 64
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double precision,parameter :: thresh = 1d-6
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double precision,external :: SigmaC,dSigmaC
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double precision :: sigC,dsigC
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double precision :: f,df
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double precision :: w
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! Output variables
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double precision,intent(out) :: eGW(nBas)
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! Run Newton's algorithm to find the root
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do p=nC+1,nBas-nR
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write(*,*) '-----------------'
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write(*,'(A10,I3)') 'Orbital ',p
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write(*,*) '-----------------'
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w = eGWlin(p)
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nIt = 0
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f = 1d0
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write(*,'(A3,I3,A1,1X,3F15.9)') 'It.',nIt,':',w*HaToeV,f
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do while (abs(f) > thresh .and. nIt < maxIt)
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nIt = nIt + 1
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sigC = SigmaC(p,w,eta,nBas,nC,nO,nV,nR,nS,eHF,Omega,rho,regularize)
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dsigC = dSigmaC(p,w,eta,nBas,nC,nO,nV,nR,nS,eHF,Omega,rho,regularize)
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f = w - eHF(p) - SigX(p) - sigC + Vxc(p)
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df = 1d0 - dsigC
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w = w - f/df
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write(*,'(A3,I3,A1,1X,3F15.9)') 'It.',nIt,':',w*HaToeV,f,sigC
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end do
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if(nIt == maxIt) then
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write(*,*) 'Newton root search has not converged!'
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else
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eGW(p) = w
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write(*,'(A32,F16.10)') 'Quasiparticle energy (eV) ',eGW(p)*HaToeV
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write(*,*)
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end if
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end do
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end subroutine QP_graph
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