mirror of https://gitlab.com/QEF/q-e.git
179 lines
5.6 KiB
Fortran
179 lines
5.6 KiB
Fortran
!
|
|
! Copyright (C) 2001-2009 Quantum ESPRESSO 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 set_irr_sym_new ( t, tmq, npertx )
|
|
!---------------------------------------------------------------------
|
|
!
|
|
! This subroutine computes:
|
|
! 1) the matrices which represent the small group of q on the
|
|
! pattern basis.
|
|
!
|
|
USE kinds, ONLY : DP
|
|
USE constants, ONLY: tpi
|
|
USE ions_base, ONLY : nat
|
|
USE cell_base, ONLY : at, bg
|
|
USE symm_base, ONLY : s, irt, t_rev
|
|
USE modes, ONLY : u, nirr, npert
|
|
USE control_flags, ONLY : modenum
|
|
USE mp, ONLY : mp_bcast
|
|
USE mp_images, ONLY : intra_image_comm
|
|
USE io_global, ONLY : ionode_id
|
|
|
|
USE qpoint, ONLY : xq
|
|
USE lr_symm_base, ONLY : nsymq, irotmq, rtau, minus_q
|
|
|
|
implicit none
|
|
!
|
|
! first the dummy variables
|
|
!
|
|
integer, intent(in) :: npertx
|
|
! input: maximum dimension of the irreducible representations
|
|
!
|
|
complex(DP), intent(out) :: t(npertx, npertx, 48, 3*nat), &
|
|
tmq (npertx, npertx, 3*nat)
|
|
! output: the symmetry matrices
|
|
! output: the matrice sending q -> -q+G
|
|
!
|
|
! here the local variables
|
|
!
|
|
integer :: na, imode, jmode, ipert, jpert, kpert, nsymtot, imode0, &
|
|
irr, ipol, jpol, isymq, irot, sna
|
|
! counters and auxiliary variables
|
|
|
|
real(DP) :: arg
|
|
! the argument of the phase
|
|
|
|
complex(DP) :: wrk_u (3, nat), wrk_ru (3, nat), fase, wrk
|
|
! pattern
|
|
! rotated pattern
|
|
! the phase factor
|
|
|
|
!
|
|
! We compute the matrices which represent the symmetry transformation
|
|
! in the basis of the displacements
|
|
!
|
|
t(:,:,:,:) = (0.d0, 0.d0)
|
|
tmq(:,:,:) = (0.d0, 0.d0)
|
|
if (minus_q) then
|
|
nsymtot = nsymq + 1
|
|
else
|
|
nsymtot = nsymq
|
|
endif
|
|
do isymq = 1, nsymtot
|
|
if (isymq.le.nsymq) then
|
|
irot = isymq
|
|
else
|
|
irot = irotmq
|
|
endif
|
|
imode0 = 0
|
|
do irr = 1, nirr
|
|
do ipert = 1, npert (irr)
|
|
if (modenum /= 0 .AND. modenum /= irr) CYCLE
|
|
imode = imode0 + ipert
|
|
do na = 1, nat
|
|
do ipol = 1, 3
|
|
jmode = 3 * (na - 1) + ipol
|
|
wrk_u (ipol, na) = u (jmode, imode)
|
|
enddo
|
|
enddo
|
|
!
|
|
! transform this pattern to crystal basis
|
|
!
|
|
do na = 1, nat
|
|
call trnvecc (wrk_u (1, na), at, bg, - 1)
|
|
enddo
|
|
!
|
|
! the patterns are rotated with this symmetry
|
|
!
|
|
wrk_ru(:,:) = (0.d0, 0.d0)
|
|
do na = 1, nat
|
|
sna = irt (irot, na)
|
|
arg = 0.d0
|
|
do ipol = 1, 3
|
|
arg = arg + xq (ipol) * rtau (ipol, irot, na)
|
|
enddo
|
|
arg = arg * tpi
|
|
if ((isymq.eq.nsymtot.and.minus_q).OR.(t_rev(isymq)==1)) then
|
|
fase = CMPLX (cos (arg), sin (arg), KIND=dp )
|
|
else
|
|
fase = CMPLX (cos (arg),-sin (arg), KIND=dp )
|
|
endif
|
|
do ipol = 1, 3
|
|
do jpol = 1, 3
|
|
wrk_ru (ipol, sna) = wrk_ru (ipol, sna) + s (jpol, ipol, irot) &
|
|
* wrk_u (jpol, na) * fase
|
|
enddo
|
|
enddo
|
|
enddo
|
|
!
|
|
! Transform back the rotated pattern
|
|
!
|
|
do na = 1, nat
|
|
call trnvecc (wrk_ru (1, na), at, bg, 1)
|
|
enddo
|
|
|
|
!
|
|
! Computes the symmetry matrices on the basis of the pattern
|
|
!
|
|
do jpert = 1, npert (irr)
|
|
imode = imode0 + jpert
|
|
do na = 1, nat
|
|
do ipol = 1, 3
|
|
jmode = ipol + (na - 1) * 3
|
|
if (isymq.eq.nsymtot.and.minus_q) then
|
|
tmq (jpert, ipert, irr) = tmq (jpert, ipert, irr) + CONJG(u ( &
|
|
jmode, imode) * wrk_ru (ipol, na) )
|
|
else
|
|
IF (t_rev(irot)==1) THEN
|
|
t (jpert,ipert,irot,irr)=t(jpert,ipert,irot,irr) &
|
|
+ CONJG(u (jmode, imode) * wrk_ru (ipol, na))
|
|
ELSE
|
|
t (jpert,ipert,irot,irr)=t(jpert,ipert,irot,irr) &
|
|
+ CONJG(u (jmode, imode) ) * wrk_ru (ipol, na)
|
|
ENDIF
|
|
endif
|
|
enddo
|
|
enddo
|
|
enddo
|
|
enddo
|
|
imode0 = imode0 + npert (irr)
|
|
|
|
!
|
|
! If the representations are irreducible, the rotations should be unitary matrices
|
|
! if this is not the case, the way the representations have been chosen has failed
|
|
! for some reasons (check set_irr.f90)
|
|
!
|
|
|
|
if(isymq<=nsymq) then
|
|
do ipert = 1, npert (irr)
|
|
IF (modenum /= 0 .AND. modenum /= irr) CYCLE
|
|
do jpert = 1, npert (irr)
|
|
wrk = (0.d0,0.d0)
|
|
do kpert = 1, npert (irr)
|
|
wrk = wrk + t (ipert,kpert,irot,irr) * conjg( t(jpert,kpert,irot,irr))
|
|
enddo
|
|
if (jpert.ne.ipert .and. abs(wrk)> 1.d-6 ) &
|
|
call errore('set_irr_sym_new','wrong representation',100*irr+10*jpert+ipert)
|
|
if (jpert.eq.ipert .and. abs(wrk-1.d0)> 1.d-6 ) &
|
|
call errore('set_irr_sym_new','wrong representation',100*irr+10*jpert+ipert)
|
|
enddo
|
|
enddo
|
|
endif
|
|
|
|
enddo
|
|
enddo
|
|
|
|
!
|
|
! parallel stuff: first node broadcasts everything to all nodes
|
|
!
|
|
call mp_bcast (t, ionode_id, intra_image_comm)
|
|
call mp_bcast (tmq, ionode_id, intra_image_comm)
|
|
return
|
|
end subroutine set_irr_sym_new
|