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https://github.com/pfloos/quack
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62 lines
1.4 KiB
Fortran
62 lines
1.4 KiB
Fortran
subroutine S51_lda_exchange_individual_energy(nEns,nGrid,weight,rhow,rho,LZx,Ex)
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! Compute the restricted version of Slater's LDA exchange individual energy
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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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integer,intent(in) :: nGrid
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double precision,intent(in) :: weight(nGrid)
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double precision,intent(in) :: rhow(nGrid,nspin)
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double precision,intent(in) :: rho(nGrid,nspin,nEns)
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! Local variables
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integer :: iG
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integer :: iEns
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integer :: ispin
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double precision :: r
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double precision :: rI
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double precision :: e
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double precision :: dedr
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! Output variables
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double precision,intent(out) :: LZx(nspin)
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double precision,intent(out) :: Ex(nspin,nEns)
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LZx(:) = 0d0
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Ex(:,:) = 0d0
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do ispin=1,nspin
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do iG=1,nGrid
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r = max(0d0,rhow(iG,ispin))
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if(r > threshold) then
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e = CxLSDA*r**(+1d0/3d0)
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dedr = 1d0/3d0*CxLSDA*r**(-2d0/3d0)
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LZx(ispin) = LZx(ispin) - weight(iG)*dedr*r*r
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do iEns=1,nEns
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rI = max(0d0,rho(iG,ispin,iEns))
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if(rI > threshold) Ex(ispin,iEns) = Ex(ispin,iEns) + weight(iG)*(e + dedr*r)*rI
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end do
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endif
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enddo
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enddo
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end subroutine S51_lda_exchange_individual_energy
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