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43 lines
810 B
Fortran
43 lines
810 B
Fortran
subroutine restricted_elda_exchange_energy(nEns,Cx,nGrid,weight,rho,Ex)
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! Compute the restricted LDA exchange energy of 2-glomium for various states
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implicit none
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include 'parameters.h'
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! Input variables
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integer,intent(in) :: nEns
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double precision,intent(in) :: Cx
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integer,intent(in) :: nGrid
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double precision,intent(in) :: weight(nGrid)
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double precision,intent(in) :: rho(nGrid)
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! Local variables
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integer :: iG
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double precision :: r
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! Output variables
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double precision,intent(out) :: Ex
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! Compute eLDA exchange energy
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Ex = 0d0
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do iG=1,nGrid
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r = max(0d0,rho(iG))
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if(r > threshold) then
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Ex = Ex + weight(iG)*Cx*r**(4d0/3d0)
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end if
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end do
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end subroutine restricted_elda_exchange_energy
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