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quack/src/eDFT/unrestricted_hybrid_correlation_energy.f90
2021-02-14 22:52:17 +01:00

57 lines
1.4 KiB
Fortran

subroutine unrestricted_hybrid_correlation_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,Ec)
! Compute the unrestricted version of the correlation energy for hybrid functionals
implicit none
include 'parameters.h'
! Input variables
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 (DFA)
case('HF')
Ec(:) = 0d0
case('LYP')
aC = 0.81d0
call unrestricted_lda_correlation_energy('VWN5 ',nEns,wEns,nGrid,weight,rho,EcLDA)
call unrestricted_gga_correlation_energy('LYP ',nEns,wEns,nGrid,weight,rho,drho,EcGGA)
Ec(:) = EcLDA(:) + aC*(EcGGA(:) - EcLDA(:))
case('PBE')
call unrestricted_gga_correlation_energy('PBE ',nEns,wEns,nGrid,weight,rho,drho,EcGGA)
Ec(:) = EcGGA(:)
case default
call print_warning('!!! Hybrid correlation energy not available !!!')
stop
end select
end subroutine unrestricted_hybrid_correlation_energy