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QuAcK/src/eDFT/unrestricted_correlation_energy.f90
2020-07-06 15:42:21 +02:00

69 lines
1.5 KiB
Fortran

subroutine unrestricted_correlation_energy(rung,DFA,nEns,wEns,nGrid,weight,rho,drho,Ec)
! Compute the unrestricted version of the correlation energy
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: rung
character(len=12),intent(in) :: DFA
integer,intent(in) :: nEns
double precision,intent(in) :: wEns(nEns)
integer,intent(in) :: nGrid
double precision,intent(in) :: weight(nGrid)
double precision,intent(in) :: rho(nGrid,nspin)
double precision,intent(in) :: drho(ncart,nGrid,nspin)
! Local variables
double precision :: EcLDA(nsp)
double precision :: EcGGA(nsp)
double precision :: aC
! Output variables
double precision,intent(out) :: Ec(nsp)
select case (rung)
! Hartree calculation
case(0)
Ec(:) = 0d0
! LDA functionals
case(1)
call unrestricted_lda_correlation_energy(DFA,nEns,wEns,nGrid,weight,rho,Ec)
! GGA functionals
case(2)
call unrestricted_gga_correlation_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,Ec)
! Hybrid functionals
case(4)
aC = 0.81d0
call unrestricted_lda_correlation_energy(DFA,nEns,wEns,nGrid,weight,rho,EcLDA)
call unrestricted_gga_correlation_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,EcGGA)
Ec(:) = EcLDA(:) + aC*(EcGGA(:) - EcLDA(:))
! Hartree-Fock calculation
case(666)
Ec(:) = 0d0
end select
end subroutine unrestricted_correlation_energy