mirror of
https://github.com/pfloos/quack
synced 2024-12-25 22:03:44 +01:00
45 lines
901 B
Fortran
45 lines
901 B
Fortran
subroutine restricted_elda_correlation_energy(nEns,aMFL,nGrid,weight,rho,Ec)
|
|
|
|
! Compute the restricted LDA correlation energy of 2-glomium for various states
|
|
|
|
implicit none
|
|
include 'parameters.h'
|
|
|
|
! Input variables
|
|
|
|
integer,intent(in) :: nEns
|
|
double precision,intent(in) :: aMFL(3)
|
|
integer,intent(in) :: nGrid
|
|
double precision,intent(in) :: weight(nGrid)
|
|
double precision,intent(in) :: rho(nGrid)
|
|
|
|
! Local variables
|
|
|
|
integer :: iG
|
|
double precision :: r,ec_p
|
|
|
|
! Output variables
|
|
|
|
double precision,intent(out) :: Ec
|
|
|
|
|
|
! Compute eLDA correlation energy
|
|
|
|
Ec = 0d0
|
|
|
|
do iG=1,nGrid
|
|
|
|
r = max(0d0,rho(iG))
|
|
|
|
if(r > threshold) then
|
|
|
|
ec_p = aMFL(1)/(1d0 + aMFL(2)*r**(-1d0/6d0) + aMFL(3)*r**(-1d0/3d0))
|
|
|
|
Ec = Ec + weight(iG)*ec_p*r
|
|
|
|
end if
|
|
|
|
end do
|
|
|
|
end subroutine restricted_elda_correlation_energy
|