quack/src/eDFT/RMFL20_lda_correlation_potential.f90

subroutine RMFL20_lda_correlation_potential(nEns,wEns,nGrid,weight,nBas,AO,rho,Fc)

! Compute Marut-Fromager-Loos weight-dependent LDA correlation potential

  implicit none
include 'parameters.h'

! Input variables

  integer,intent(in)            :: nEns
  double precision,intent(in)   :: wEns(nEns)
  integer,intent(in)            :: nGrid
  double precision,intent(in)   :: weight(nGrid)
  integer,intent(in)            :: nBas
  double precision,intent(in)   :: AO(nBas,nGrid)
  double precision,intent(in)   :: rho(nGrid)

! Local variables

  integer                       :: iEns
  double precision,allocatable  :: aMFL(:,:)
  double precision,allocatable  :: FcLDA(:,:)
  double precision,allocatable  :: FceLDA(:,:,:)

! Output variables

  double precision,intent(out)  :: Fc(nBas,nBas)

! Allocation

  allocate(aMFL(3,nEns),FcLDA(nBas,nBas),FceLDA(nBas,nBas,nEns))

! Parameters for weight-dependent LDA correlation functional

  aMFL(1,1) = -0.0238184d0
  aMFL(2,1) = +0.00540994d0
  aMFL(3,1) = +0.0830766d0

  aMFL(1,2) = -0.0144633d0
  aMFL(2,2) = -0.0506019d0
  aMFL(3,2) = +0.0331417d0

! Compute correlation energy for ground, singly-excited and doubly-excited states

  do iEns=1,nEns

    call restricted_elda_correlation_potential(nEns,aMFL(:,iEns),nGrid,weight,nBas,AO,rho,FceLDA(:,:,iEns))

  end do

! LDA-centered functional

  FcLDA(:,:) = 0d0

  call RVWN5_lda_correlation_potential(nGrid,weight,nBas,AO,rho,FcLDA)

  do iEns=1,nEns

    FceLDA(:,:,iEns) = FceLDA(:,:,iEns) + FcLDA(:,:) - FceLDA(:,:,1)

  end do

! Weight-denpendent functional for ensembles

  Fc(:,:) = 0d0

  do iEns=1,nEns

    Fc(:,:) = Fc(:,:) + wEns(iEns)*FceLDA(:,:,iEns)

  enddo

end subroutine RMFL20_lda_correlation_potential