mirror of
https://github.com/pfloos/quack
synced 2024-09-06 19:54:45 +02:00
39 lines
691 B
Fortran
39 lines
691 B
Fortran
subroutine RS51_lda_exchange_energy(nGrid,weight,rho,Ex)
|
|
|
|
! Compute restriced version of Slater's LDA exchange energy
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
integer,intent(in) :: nGrid
|
|
double precision,intent(in) :: weight(nGrid)
|
|
double precision,intent(in) :: rho(nGrid)
|
|
|
|
! Local variables
|
|
|
|
integer :: iG
|
|
double precision :: r
|
|
|
|
! Output variables
|
|
|
|
double precision :: Ex
|
|
|
|
! Compute LDA exchange energy
|
|
|
|
Ex = 0d0
|
|
do iG=1,nGrid
|
|
|
|
r = max(0d0,rho(iG))
|
|
|
|
if(r > threshold) then
|
|
|
|
Ex = Ex + weight(iG)*CxLDA*r**(4d0/3d0)
|
|
|
|
endif
|
|
|
|
enddo
|
|
|
|
end subroutine RS51_lda_exchange_energy
|