quantum-espresso/PW/divide_et_impera.f90

99 lines
2.7 KiB
Fortran

!
! Copyright (C) 2001-2004 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 .
!
#include "f_defs.h"
!
!----------------------------------------------------------------------------
SUBROUTINE divide_et_impera( xk, wk, isk, lsda, nkstot, nks )
!----------------------------------------------------------------------------
!
! ... This routine divides the k points (with granularity kunit) among nodes
! ... and sets the variable nkstot equal to the total number of k-points
!
USE io_global, only : stdout
USE kinds, ONLY : DP
USE mp_global, ONLY : my_pool_id, npool, kunit
#if defined (EXX)
USE exx, ONLY : lexx, index_xk, index_xkq, nkqs, nqs
#endif
!
IMPLICIT NONE
!
LOGICAL :: lsda
! logical for local spin density approx.
INTEGER :: nkstot, nks, isk(nks)
! total number of k-points
! number of k-points per pool
! spin index of each kpoint (when lsda=.t.)
REAL (DP) :: xk(3,nks), wk(nks)
! k-points
! k-point weights
#if defined (EXX)
INTEGER :: ikk, iq
#endif
!
#if defined (__PARA)
!
INTEGER :: ik, nbase, rest
!
!
IF ( MOD( nks, kunit ) /= 0 ) &
CALL errore( 'd_&_i', ' nks/kunit is not an integer', nks )
!
nkstot = nks
nks = kunit * ( nkstot / kunit / npool )
!
IF ( nks == 0 ) CALL errore( 'd_&_i', ' nks = 0 for some nodes', 1 )
!
rest = ( nkstot - nks * npool ) / kunit
!
IF ( ( my_pool_id + 1 ) <= rest ) nks = nks + kunit
!
! ... calculates nbase = the position in the list of the first point that
! ... belong to this npool - 1
!
nbase = nks * my_pool_id
!
IF ( ( my_pool_id + 1 ) > rest ) nbase = nbase + rest * kunit
!
! ... displaces these points in the first positions of the list
!
IF ( nbase > 0 ) THEN
!
xk(:,1:nks) = xk(:,nbase+1:nbase+nks)
!
wk(1:nks) = wk(nbase+1:nbase+nks)
!
IF ( lsda ) isk(1:nks) = isk(nbase+1:nbase+nks)
!
#if defined (EXX)
IF ( lexx ) THEN
index_xk(1:nkqs) = index_xk(1:nkqs) - nbase
index_xkq(1:nks,1:nqs) = index_xkq(nbase+1:nbase+nks,1:nqs)
!
! consistency check
!
do ik=1,nks
do iq =1,nqs
ikk = index_xk(index_xkq(ik,iq))
if ( ikk < 1 .or. ikk > nks ) then
write (stdout,*) ik, iq, index_xkq(ik,iq), ikk
call errore ('d_&_i',' error in EXX indexing',1)
end if
end do
end do
END IF
#endif
END IF
!
#endif
!
RETURN
!
END SUBROUTINE divide_et_impera