mirror of https://gitlab.com/QEF/q-e.git
158 lines
4.8 KiB
Fortran
158 lines
4.8 KiB
Fortran
!
|
|
! Copyright (C) 2001 PWSCF group
|
|
! This file is distributed under the terms of the
|
|
! GNU General Public License. See the file `License'
|
|
! in the root directory of the present distribution,
|
|
! or http://www.gnu.org/copyleft/gpl.txt .
|
|
!
|
|
!
|
|
!----------------------------------------------------------------------
|
|
subroutine dvqpsi_us_only (ik, mode, uact)
|
|
!----------------------------------------------------------------------
|
|
!
|
|
! This routine calculates dV_bare/dtau * psi for one perturbation
|
|
! with a given q. The displacements are described by a vector uact.
|
|
! The result is stored in dvpsi. The routine is called for each k point
|
|
! and for each pattern u. It computes simultaneously all the bands.
|
|
!
|
|
#include "f_defs.h"
|
|
!
|
|
USE ions_base, ONLY : nat, ityp, ntyp => nsp
|
|
use pwcom
|
|
USE kinds, only : DP
|
|
USE uspp_param, ONLY: nh
|
|
use phcom
|
|
implicit none
|
|
!
|
|
! The dummy variables
|
|
!
|
|
|
|
integer :: ik, mode
|
|
! input: the k point
|
|
! input: the actual perturbation
|
|
complex(DP) :: uact (3 * nat)
|
|
! input: the pattern of displacements
|
|
!
|
|
! And the local variables
|
|
!
|
|
|
|
integer :: na, nb, mu, nu, ikk, ikq, ig, igg, nt, ibnd, ijkb0, &
|
|
ikb, jkb, ih, jh, ipol
|
|
! counter on atoms
|
|
! counter on modes
|
|
! the point k
|
|
! the point k+q
|
|
! counter on G vectors
|
|
! auxiliary counter on G vectors
|
|
! counter on atomic types
|
|
! counter on bands
|
|
! auxiliary variable for counting
|
|
! counter on becp functions
|
|
! counter on becp functions
|
|
! counter on n index
|
|
! counter on m index
|
|
! counter on polarizations
|
|
|
|
real(DP), parameter :: eps = 1.d-12
|
|
|
|
complex(DP), allocatable :: ps1 (:,:), ps2 (:,:,:), aux (:)
|
|
! work space
|
|
|
|
logical :: ok
|
|
|
|
call start_clock ('dvqpsi_us_on')
|
|
allocate (ps1 ( nkb , nbnd))
|
|
allocate (ps2 ( nkb , nbnd , 3))
|
|
allocate (aux ( npwx))
|
|
if (lgamma) then
|
|
ikk = ik
|
|
ikq = ik
|
|
else
|
|
ikk = 2 * ik - 1
|
|
ikq = ikk + 1
|
|
endif
|
|
if (lsda) current_spin = isk (ikk)
|
|
!
|
|
! we first compute the coefficients of the vectors
|
|
!
|
|
ps1(:,:) = (0.d0, 0.d0)
|
|
ps2(:,:,:) = (0.d0, 0.d0)
|
|
ijkb0 = 0
|
|
do nt = 1, ntyp
|
|
do na = 1, nat
|
|
if (ityp (na) .eq.nt) then
|
|
mu = 3 * (na - 1)
|
|
do ih = 1, nh (nt)
|
|
ikb = ijkb0 + ih
|
|
do jh = 1, nh (nt)
|
|
jkb = ijkb0 + jh
|
|
do ipol = 1, 3
|
|
do ibnd = 1, nbnd
|
|
if ( abs (uact (mu + 1) ) + &
|
|
abs (uact (mu + 2) ) + &
|
|
abs (uact (mu + 3) ) > eps) then
|
|
ps1 (ikb, ibnd) = ps1 (ikb, ibnd) + &
|
|
(deeq (ih, jh, na, current_spin) - &
|
|
et (ibnd, ikk) * qq (ih, jh, nt) ) * &
|
|
alphap(jkb, ibnd, ipol, ik) * uact (mu + ipol)
|
|
ps2 (ikb, ibnd, ipol) = ps2 (ikb, ibnd, ipol) +&
|
|
(deeq (ih,jh, na, current_spin) - &
|
|
et (ibnd, ikk) * qq (ih, jh, nt) ) * &
|
|
(0.d0, -1.d0) * becp1 (jkb, ibnd, ik) * &
|
|
uact (mu + ipol) * tpiba
|
|
if (okvan) then
|
|
ps1 (ikb, ibnd) = ps1 (ikb, ibnd) + &
|
|
(int1 (ih, jh, ipol,na, current_spin) * &
|
|
becp1 (jkb, ibnd, ik) ) * uact (mu +ipol)
|
|
endif
|
|
endif
|
|
if (okvan) then
|
|
do nb = 1, nat
|
|
nu = 3 * (nb - 1)
|
|
ps1 (ikb, ibnd) = ps1 (ikb, ibnd) + &
|
|
(int2 (ih, jh, ipol, nb, na) * &
|
|
becp1 (jkb, ibnd, ik) ) * uact (nu + ipol)
|
|
enddo
|
|
endif
|
|
enddo
|
|
enddo
|
|
enddo
|
|
enddo
|
|
ijkb0 = ijkb0 + nh (nt)
|
|
endif
|
|
enddo
|
|
enddo
|
|
!
|
|
! This term is proportional to beta(k+q+G)
|
|
!
|
|
if (nkb.gt.0) call ZGEMM ('N', 'N', npwq, nbnd, nkb, &
|
|
(1.d0, 0.d0) , vkb, npwx, ps1, nkb, (1.d0, 0.d0) , dvpsi, npwx)
|
|
!
|
|
! This term is proportional to (k+q+G)_\alpha*beta(k+q+G)
|
|
!
|
|
do ikb = 1, nkb
|
|
do ipol = 1, 3
|
|
ok = .false.
|
|
do ibnd = 1, nbnd
|
|
ok = ok.or. (abs (ps2 (ikb, ibnd, ipol) ) .gt.eps)
|
|
enddo
|
|
if (ok) then
|
|
do ig = 1, npwq
|
|
igg = igkq (ig)
|
|
aux (ig) = vkb(ig, ikb) * (xk(ipol, ikq) + g(ipol, igg) )
|
|
enddo
|
|
do ibnd = 1, nbnd
|
|
call ZAXPY (npwq, ps2(ikb,ibnd,ipol), aux, 1, dvpsi(1,ibnd), 1)
|
|
enddo
|
|
endif
|
|
enddo
|
|
|
|
enddo
|
|
deallocate (aux)
|
|
deallocate (ps2)
|
|
deallocate (ps1)
|
|
|
|
call stop_clock ('dvqpsi_us_on')
|
|
return
|
|
end subroutine dvqpsi_us_only
|