mirror of https://gitlab.com/QEF/q-e.git
176 lines
6.4 KiB
Fortran
176 lines
6.4 KiB
Fortran
!
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! Copyright (C) 2001-2016 Quantum ESPRESSO 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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!-----------------------------------------------------------------------
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subroutine setup_dgc
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!-----------------------------------------------------------------------
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!
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! Allocate and setup all variable needed in the gradient correction case
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!
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! GGA+LSDA is allowed. ADC (September 1999).
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! GGA+LSDA+NLCC is allowed. ADC (November 1999).
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! GGA+noncollinear+NLCC is allowed. ADC (June 2007).
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!
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USE constants, ONLY : e2
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USE fft_base, ONLY : dfftp
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USE fft_interfaces, ONLY : fwfft
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USE gvect, ONLY : ngm, g, nl
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USE spin_orb, ONLY : domag
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USE scf, ONLY : rho, rho_core, rhog_core
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USE noncollin_module, ONLY : noncolin, ux, nspin_gga, nspin_mag
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USE wavefunctions_module, ONLY : psic
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USE kinds, ONLY : DP
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USE funct, ONLY : dft_is_gradient, gcxc, gcx_spin, &
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gcc_spin, dgcxc, dgcxc_spin
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USE uspp, ONLY : nlcc_any
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USE gc_lr, ONLY : grho, gmag, dvxc_rr, dvxc_sr, &
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dvxc_ss, dvxc_s, vsgga, segni
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implicit none
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integer :: k, is, ipol, jpol, ir
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real(DP) :: grho2 (2), rh, zeta, grh2, fac, sx, sc, &
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v1x, v2x, v1c, v2c, vrrx, vsrx, vssx, vrrc, vsrc, vssc, v1xup, &
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v1xdw, v2xup, v2xdw, v1cup, v1cdw, vrrxup, vrrxdw, vrsxup, vrsxdw, &
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vssxup, vssxdw, vrrcup, vrrcdw, vrscup, vrscdw, vrzcup, vrzcdw, &
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amag, seg, seg0
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COMPLEX(DP), ALLOCATABLE :: rhogout(:,:)
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real(DP), allocatable :: rhoout(:,:)
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real (DP), parameter :: epsr = 1.0d-6, epsg = 1.0d-10
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IF ( .NOT. dft_is_gradient() ) RETURN
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IF (noncolin.AND.domag) THEN
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allocate (segni (dfftp%nnr))
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allocate (vsgga (dfftp%nnr))
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allocate (gmag (3, dfftp%nnr, nspin_mag))
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gmag=0.0_dp
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ENDIF
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IF(.NOT.ALLOCATED(dvxc_rr)) ALLOCATE (dvxc_rr(dfftp%nnr, nspin_gga , nspin_gga))
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IF(.NOT.ALLOCATED(dvxc_sr)) ALLOCATE (dvxc_sr(dfftp%nnr, nspin_gga , nspin_gga))
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IF(.NOT.ALLOCATED(dvxc_ss)) ALLOCATE (dvxc_ss(dfftp%nnr, nspin_gga , nspin_gga))
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IF(.NOT.ALLOCATED(dvxc_s)) ALLOCATE (dvxc_s (dfftp%nnr, nspin_gga , nspin_gga))
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IF(.NOT.ALLOCATED(grho)) ALLOCATE (grho ( 3 , dfftp%nnr, nspin_gga))
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IF(.NOT.ALLOCATED(rhoout)) ALLOCATE (rhoout ( dfftp%nnr, nspin_gga))
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dvxc_rr(:,:,:) = 0.d0
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dvxc_sr(:,:,:) = 0.d0
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dvxc_ss(:,:,:) = 0.d0
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dvxc_s (:,:,:) = 0.d0
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grho (:,:,:) = 0.d0
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!
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! add rho_core
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!
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fac = 1.d0 / DBLE (nspin_gga)
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IF (noncolin.and.domag) THEN
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allocate(rhogout(ngm,nspin_mag))
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call compute_rho(rho%of_r,rhoout,segni,dfftp%nnr)
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DO is = 1, nspin_gga
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!
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if (nlcc_any) rhoout(:,is) = fac * rho_core(:) + rhoout(:,is)
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psic(:) = rhoout(:,is)
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!
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CALL fwfft ('Dense', psic, dfftp)
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!
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rhogout(:,is) = psic(nl(:))
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!
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!
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CALL gradrho(dfftp%nnr, rhogout(1,is), ngm, g, nl, grho(1,1,is) )
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!
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END DO
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DEALLOCATE(rhogout)
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ELSE
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do is = 1, nspin_gga
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rhoout(:,is) = rho%of_r(:,is)
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enddo
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if (nlcc_any) then
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do is = 1, nspin_gga
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rhoout(:,is) = fac * rho_core(:) + rho%of_r(:,is)
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rho%of_g(:,is) = fac * rhog_core(:) + rho%of_g(:,is)
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enddo
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endif
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do is = 1, nspin_gga
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call gradrho (dfftp%nnr, rho%of_g (1, is), ngm, g, nl, grho (1, 1, is) )
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enddo
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END IF
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do k = 1, dfftp%nnr
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grho2 (1) = grho (1, k, 1) **2 + grho (2, k, 1) **2 + grho (3, k, 1) **2
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if (nspin_gga == 1) then
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if (abs (rhoout (k, 1) ) > epsr .and. grho2 (1) > epsg) then
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call gcxc (rhoout (k, 1), grho2(1), sx, sc, v1x, v2x, v1c, v2c)
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call dgcxc (rhoout (k, 1), grho2(1), vrrx, vsrx, vssx, vrrc, &
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vsrc, vssc)
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dvxc_rr (k, 1, 1) = e2 * (vrrx + vrrc)
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dvxc_sr (k, 1, 1) = e2 * (vsrx + vsrc)
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dvxc_ss (k, 1, 1) = e2 * (vssx + vssc)
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dvxc_s (k, 1, 1) = e2 * (v2x + v2c)
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endif
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else
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grho2 (2) = grho(1, k, 2) **2 + grho(2, k, 2) **2 + grho(3, k, 2) **2
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rh = rhoout (k, 1) + rhoout (k, 2)
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grh2 = (grho (1, k, 1) + grho (1, k, 2) ) **2 + (grho (2, k, 1) &
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+ grho (2, k, 2) ) **2 + (grho (3, k, 1) + grho (3, k, 2) ) ** 2
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call gcx_spin (rhoout (k, 1), rhoout (k, 2), grho2 (1), grho2 (2), &
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sx, v1xup, v1xdw, v2xup, v2xdw)
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call dgcxc_spin (rhoout (k, 1), rhoout (k, 2), grho (1, k, 1), &
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grho (1, k, 2), vrrxup, vrrxdw, vrsxup, vrsxdw, vssxup, vssxdw, &
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vrrcup, vrrcdw, vrscup, vrscdw, vssc, vrzcup, vrzcdw)
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if (rh > epsr) then
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zeta = (rhoout (k, 1) - rhoout (k, 2) ) / rh
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call gcc_spin (rh, zeta, grh2, sc, v1cup, v1cdw, v2c)
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dvxc_rr (k, 1, 1) = e2 * (vrrxup + vrrcup + vrzcup * &
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(1.d0 - zeta) / rh)
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dvxc_rr (k, 1, 2) = e2 * (vrrcup - vrzcup * (1.d0 + zeta) / rh)
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dvxc_rr (k, 2, 1) = e2 * (vrrcdw + vrzcdw * (1.d0 - zeta) / rh)
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dvxc_rr (k, 2, 2) = e2 * (vrrxdw + vrrcdw - vrzcdw * &
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(1.d0 + zeta) / rh)
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dvxc_s (k, 1, 1) = e2 * (v2xup + v2c)
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dvxc_s (k, 1, 2) = e2 * v2c
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dvxc_s (k, 2, 1) = e2 * v2c
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dvxc_s (k, 2, 2) = e2 * (v2xdw + v2c)
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else
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dvxc_rr (k, 1, 1) = 0.d0
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dvxc_rr (k, 1, 2) = 0.d0
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dvxc_rr (k, 2, 1) = 0.d0
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dvxc_rr (k, 2, 2) = 0.d0
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dvxc_s (k, 1, 1) = 0.d0
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dvxc_s (k, 1, 2) = 0.d0
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dvxc_s (k, 2, 1) = 0.d0
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dvxc_s (k, 2, 2) = 0.d0
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endif
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dvxc_sr (k, 1, 1) = e2 * (vrsxup + vrscup)
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dvxc_sr (k, 1, 2) = e2 * vrscup
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dvxc_sr (k, 2, 1) = e2 * vrscdw
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dvxc_sr (k, 2, 2) = e2 * (vrsxdw + vrscdw)
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dvxc_ss (k, 1, 1) = e2 * (vssxup + vssc)
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dvxc_ss (k, 1, 2) = e2 * vssc
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dvxc_ss (k, 2, 1) = e2 * vssc
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dvxc_ss (k, 2, 2) = e2 * (vssxdw + vssc)
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endif
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enddo
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if (noncolin.and.domag) then
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call compute_vsgga(rhoout, grho, vsgga)
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else
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if (nlcc_any) then
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do is = 1, nspin_gga
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rho%of_g(:,is) = rho%of_g(:,is) - fac * rhog_core(:)
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enddo
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endif
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endif
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DEALLOCATE(rhoout)
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RETURN
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end subroutine setup_dgc
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