mirror of
https://github.com/pfloos/quack
synced 2024-08-15 00:58:34 +02:00
43 lines
985 B
Fortran
43 lines
985 B
Fortran
|
subroutine gga_correlation_energy(DFA,nEns,wEns,nGrid,weight,rho,drho,Ec)
|
||
|
|
||
|
! Compute GGA correlation energy
|
||
|
|
||
|
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
|
||
|
|
||
|
integer :: iG
|
||
|
double precision :: ra,rb,ga,gb
|
||
|
|
||
|
! Output variables
|
||
|
|
||
|
double precision :: Ec(nsp)
|
||
|
|
||
|
! Coefficients for ??? GGA exchange functional
|
||
|
|
||
|
! Compute GGA exchange energy
|
||
|
|
||
|
Ec(:) = 0d0
|
||
|
|
||
|
do iG=1,nGrid
|
||
|
|
||
|
ra = rho(iG,1)
|
||
|
rb = rho(iG,2)
|
||
|
ga = drho(1,iG,1)**2 + drho(2,iG,1)**2 + drho(3,iG,1)**2
|
||
|
gb = drho(1,iG,2)**2 + drho(2,iG,2)**2 + drho(3,iG,2)**2
|
||
|
|
||
|
enddo
|
||
|
|
||
|
end subroutine gga_correlation_energy
|