mirror of https://gitlab.com/QEF/q-e.git
159 lines
4.5 KiB
Fortran
159 lines
4.5 KiB
Fortran
!
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! Copyright (C) 2001-2003 PWSCF group
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! This file is distributed under the terms of the
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! GNU General Public License. See the file `License'
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! in the root directory of the present distribution,
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! or http://www.gnu.org/copyleft/gpl.txt .
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!
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subroutine work_function (wf)
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!
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! Print out the workfunction, calculated as the difference between the
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! potential energy and the fermi energy.
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! Written for supercells with the main axis along z.
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!
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USE constants, ONLY: rytoev, e2
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USE io_global, ONLY : stdout
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USE ener, ONLY: ef
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USE lsda_mod, ONLY: nspin, current_spin
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USE scf, ONLY: rho, vltot, vr, rho_core
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USE gvect
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USE cell_base, ONLY : omega, alat
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#ifdef __PARA
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use para
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use mp
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#endif
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implicit none
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integer :: ionode_id = 0
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real(kind=DP) :: wmean1, wmean2, meancharge, wx1, wx2, wxm, vx, vc, ex, &
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ec, rhox, rs, vcca, wf, etxc, vtxc
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integer :: n1, n2, ni, nmean
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logical :: exst
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real(kind=DP), allocatable :: raux1 (:), vaux1 (:), vaux2(:), aux (:)
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real(kind=DP), allocatable :: vxc(:,:)
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! auxiliary vectors for charge and potential
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allocate (raux1( nrx1 * nrx2 * nrx3))
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allocate (vaux1( nrx1 * nrx2 * nrx3))
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allocate (vaux2( nrx1 * nrx2 * nrx3))
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if (nspin .eq. 4) &
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call errore ('work_function','spin-orbit not implemented',1)
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allocate (vxc(nrxx,nspin))
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call v_xc (rho, rho_core, nr1, nr2, nr3, nrx1, nrx2, nrx3, nrxx, &
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nl, ngm, g, nspin, alat, omega, etxc, vtxc, vxc)
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#ifdef __PARA
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if (me.eq.1.and.mypool.eq.1) then
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#endif
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call seqopn (17, 'workf', 'formatted', exst)
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call seqopn (19, 'charge', 'formatted', exst)
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#ifdef __PARA
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endif
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#endif
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wf = 0.d0
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do current_spin=1,nspin
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#ifdef __PARA
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allocate (aux ( nrxx))
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aux(:) = rho(:,current_spin) + rho_core(:)/nspin
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call gather (aux, raux1)
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#else
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raux1(1:nrxx) = rho(1:nrxx,current_spin) + rho_core(1:nrxx)/nspin
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#endif
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!
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!
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#ifdef __PARA
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aux(:) = vltot(:) + vr(:,current_spin)
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call gather (aux, vaux1)
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aux(:) = aux(:) - vxc(:,current_spin)
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call gather (aux, vaux2)
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#else
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vaux1(1:nrxx) = vltot(1:nrxx) + vr(1:nrxx,current_spin)
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vaux2(1:nrxx) = vaux1(1:nrxx) -vxc(1:nrxx,current_spin)
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#endif
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!
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#ifdef __PARA
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deallocate(aux)
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if (me.eq.1.and.mypool.eq.1) then
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#endif
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if (nspin.eq.2) then
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if (current_spin.eq.1) then
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WRITE(17,*) " SPIN UP "
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WRITE(19,*) " SPIN UP "
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else
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WRITE(17,*) " SPIN DOWN "
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WRITE(19,*) " SPIN DOWN "
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end if
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endif
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do nmean = 1, nr3
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wmean1 = 0.d0
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wmean2 = 0.d0
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meancharge = 0.d0
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wx1 = 0.d0
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wx2 = 0.d0
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wxm = 0.d0
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do n2 = 1, nr2
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do n1 = 1, nr1
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ni = n1 + (n2 - 1) * nrx1 + (nmean - 1) * nrx1 * nrx2
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meancharge = meancharge+raux1 (ni)
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wxm = wxm + raux1 (ni) **2
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wmean1 = wmean1 + vaux1 (ni)
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wx1 = wx1 + vaux1 (ni) **2
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wmean2 = wmean2 + vaux2 (ni)
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wx2 = wx2 + vaux2 (ni) **2
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enddo
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enddo
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wmean1 = wmean1 / dble (nr1 * nr2)
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wmean2 = wmean2 / dble (nr1 * nr2)
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meancharge = meancharge / dble (nr1 * nr2)
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wx1 = dsqrt (wx1 / dble (nr1 * nr2) - wmean1 * wmean1)
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wx2 = dsqrt (wx2 / dble (nr1 * nr2) - wmean2 * wmean2)
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wxm = dsqrt (wxm / dble (nr1 * nr2) - meancharge**2)
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if (nmean.eq. (nr3 + 1) / 2) then
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wf = wf + (wmean2 - ef)
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if (nspin.eq.2) then
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if (current_spin.eq.1) then
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WRITE( stdout,*) " SPIN UP "
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else
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WRITE( stdout,*) " SPIN DOWN "
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end if
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endif
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WRITE( stdout, 9130) rytoev * (wmean1 - ef), wx1 * rytoev, &
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rytoev * (wmean2 - ef), wx2 * rytoev
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end if
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write (17, * ) nmean, (wmean1 - ef) * rytoev, wx1 * rytoev, &
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(wmean2 - ef) * rytoev, wx2 * rytoev
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write (19, * ) nmean, meancharge, wxm
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enddo
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#ifdef __PARA
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endif
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#endif
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end do
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wf = wf / nspin
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#ifdef __PARA
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CALL mp_bcast( wf, ionode_id )
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#endif
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WRITE( stdout, '(/5x,"Work function written on file workf")')
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WRITE( stdout, '( 5x,"Planar mean charge written on file charge")')
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9130 format (/' workfunction = ',f10.4,' +- ',f10.4,' eV', &
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& /' without exchcorr = ',f10.4,' +- ',f10.4,' eV')
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close (17)
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close (19)
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deallocate(raux1)
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deallocate(vaux1)
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deallocate(vaux2)
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deallocate(vxc)
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return
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end subroutine work_function
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