!
! Copyright (C) 2001-2003 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 .
!
!----------------------------------------------------------------------------
!
MODULE el_phon 
  USE kinds, ONLY :  DP
  !
  SAVE
  !
  COMPLEX(KIND=DP), ALLOCATABLE :: &
       el_ph_mat  (:,:,:,:),   &!  e-p matrix  (nbnd, nbnd, nks, 3*nat)
       cu(:,:,:),              &!  rot matrix for wannier interpolation, coarse mesh (nbnd*nbnd*nkstot)
       umat(:,:,:),            &!  the rotation matrix for the unique setting of the wfs gauge
       dynq  (:,:,:),          &!  dynamical matrix for every q (nmode, nmodes, nqtot)
       epmatq (:,:,:,:,:)       !  e-p matrix for every q (nbnd, nbnd, nks, nmodes, nqtot)
  REAL(KIND=DP), ALLOCATABLE :: &
       xk_all(:,:),            &!  full k point grid, coarse (3, nkstot)
       et_all(:,:),            &!  full eigenvalue list, coarse (nbnd, nkstot)
       xkf(:,:),               &!  fine k point grid (3, nksf)
       wkf(:),                 &!  weights on the fine grid (nksf)
       xqf(:,:),               &!  fine q point grid 
       wqf(:),                 &!  weights on the fine q grid 
       etf(:,:),               &!  interpolated eigenvalues (nbnd, nksf)
       wf(:,:),                &!  interpolated eigenfrequencies 
       wslen(:)                !   length of the wigner seitz points in units of alat
  INTEGER :: &
       nkbl,                   &!  number of k points blocks ( = nkstot at gamma, = nkstot/2 for q /= 0)
       nksf,                   &!  number of k points in the pool (fine grid)
       nksqf,                  &!  number of k blocks in the pool (fine grid)
       nkstotf,                &!  total number of k points (fine grid)
       nxqf,                   &!  total number of q points (fine grid)
       nrr,                    &!  number of wigner-seitz points (elec interp only)
       nrr_k,                  &!  number of wigner-seitz points for electrons
       nrr_q,                  &!  number of wigner-seitz points for phonons
       ibndmin,                &!  band bounds for slimming down electron-phonon matrix 
       ibndmax                  !
  INTEGER, ALLOCATABLE ::      & 
       irvec(:,:),             &!  crys coordinates of wigner-seitz vectors (both elec and phon)
       ndegen(:),              &!  corresponding degeneragy, electrons (old version)
       ndegen_k(:),            &!  corresponding degeneragy, electrons
       ndegen_q(:)              !  corresponding degeneragy, phonons
  INTEGER, allocatable ::       &
       shift (:),              &!  for every k+q, index of the G0 which folds k+q into k+q+G0 of the first BZ
       gmap(:)                  !  the map G -> G-G_0 in the large (density) G vectors set, for every G_0
END MODULE el_phon