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QuAcK/src/eDFT/unrestricted_gga_exchange_energy.f90

41 lines
919 B
Fortran

subroutine unrestricted_gga_exchange_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,Ex)
! Select GGA exchange functional for energy calculation
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)
double precision,intent(in) :: drho(3,nGrid)
! Output variables
double precision :: Ex
select case (DFA)
case ('G96')
call UG96_gga_exchange_energy(nGrid,weight,rho,drho,Ex)
case ('B88')
call UB88_gga_exchange_energy(nGrid,weight,rho,drho,Ex)
case default
call print_warning('!!! GGA exchange energy not available !!!')
stop
end select
end subroutine unrestricted_gga_exchange_energy