quantum-espresso/PHonon/PH/symdyn_munu.f90

94 lines
2.5 KiB
Fortran

!
! Copyright (C) 2001-2012 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 symdyn_munu_new( dyn, u, xq, s, invs, rtau, irt, at, &
bg, nsymq, nat, irotmq, minus_q )
!-----------------------------------------------------------------------
!! This routine symmetrize the dynamical matrix written in the basis
!! of the modes.
USE kinds, only : DP
implicit none
integer :: nat
!1 input: the number of atoms
integer :: s(3,3,48)
!! input: the symmetry matrices
integer :: irt(48,nat)
!! input: the rotated of each atom
integer :: invs(48)
!! input: the inverse of each matrix
integer :: nsymq
!! input: the order of the small group
integer :: irotmq
!! input: the small group of q.
!! input: the symmetry q -> -q+G
real(DP) :: xq(3)
!! input: the coordinates of q
real(DP) :: rtau(3,48,nat)
!! input: the R associated at each r
real(DP) :: at(3,3)
!! input: direct lattice vectors
real(DP) :: bg(3,3)
!! input: reciprocal lattice vectors
logical :: minus_q
!! input: if true symmetry sends q-> -q+G
complex(DP) :: dyn(3*nat,3*nat)
!! inp/out: matrix to symmetrize
complex(DP) :: u(3*nat,3*nat)
!! input: the patterns
!
! ... local variables
!
integer :: i, j, icart, jcart, na, nb, mu, nu
! counter on modes
! counter on modes
! counter on cartesian coordinates
! counter on cartesian coordinates
! counter on atoms
! counter on atoms
! counter on modes
! counter on modes
complex(DP) :: work, phi (3, 3, nat, nat)
! auxiliary variable
! the dynamical matrix
!
! First we transform in the cartesian coordinates
!
CALL dyn_pattern_to_cart(nat, u, dyn, phi)
!
! Then we transform to the crystal axis
!
do na = 1, nat
do nb = 1, nat
call trntnsc (phi (1, 1, na, nb), at, bg, - 1)
enddo
enddo
!
! And we symmetrize in this basis
!
call symdynph_gq_new (xq, phi, s, invs, rtau, irt, nsymq, nat, &
irotmq, minus_q)
!
! Back to cartesian coordinates
!
do na = 1, nat
do nb = 1, nat
call trntnsc (phi (1, 1, na, nb), at, bg, + 1)
enddo
enddo
!
! rewrite the dynamical matrix on the array dyn with dimension 3nat x 3nat
!
CALL compact_dyn(nat, dyn, phi)
return
end subroutine symdyn_munu_new