quantum-espresso/PW/rho2zeta.f90

!
! 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 .
!
!----------------------------------------------------------------------------
SUBROUTINE rho2zeta( rho, rho_core, nrxx, nspin, iop )
  !---------------------------------------------------------------------------
  !
  ! ... if ( iopi == 1 )  transform the spin up spin down charge density 
  ! ...                   rho(*,is) into :
  !
  ! ...                      rho(*,1) = ( rho_up + rho_dw ) and
  ! ...                      rho(*,2) = ( rho_up - rho_dw ) / rho_tot = zeta
  !
  ! ... if ( iopi == -1)  do the opposit transformation
  !
  USE constants, ONLY : eps32
  USE io_global, ONLY : stdout
  USE kinds,     ONLY : DP
  !
  IMPLICIT NONE
  !
  INTEGER :: iop, nspin, nrxx, ir
    ! the input option
    ! the number of spin polarizations
    ! the fft grid dimension
    ! the counter for fft grid
  REAL(DP) :: rho(nrxx,nspin), rho_core(nrxx), &
                   rho_up, rho_dw, zeta, rhox
    ! the scf charge density
    ! the core charge density
    ! auxiliary variable for rho up
    ! auxiliary variable for rho dw
    ! auxiliary variable for zeta
    ! auxiliary variable for total rho
  !
  !
  IF ( nspin == 1 ) RETURN
  !
  IF ( iop == 1 ) THEN
     !
     DO ir = 1, nrxx
        !
        rhox = rho(ir,1) + rho(ir,2) + rho_core(ir)
        !
        IF ( rhox > eps32 ) THEN
           !
           zeta = ( rho(ir,1) - rho(ir,2) ) / rhox
           !
        ELSE
           !
           zeta = 0.D0
           !
        END IF
        !
        rho(ir,1) = rho(ir,1) + rho(ir,2)
        rho(ir,2) = zeta
        !
     END DO
     !
  ELSE IF ( iop == - 1 ) THEN
     !
     DO ir = 1, nrxx
        !
        rhox = rho(ir,1) + rho_core(ir)
        !
        rho_up = 0.5D0 * ( rho(ir,1) + rho(ir,2) * rhox )
        rho_dw = 0.5D0 * ( rho(ir,1) - rho(ir,2) * rhox )
        !
        rho(ir,1) = rho_up
        rho(ir,2) = rho_dw
        !
     END DO
     !
  ELSE
     !
     WRITE( stdout , '(5X,"iop = ",I5)' ) iop
     !
     CALL errore( 'mag2zeta', 'wrong iop', 1 )
     !
  END IF
  !
  RETURN
  !
END SUBROUTINE rho2zeta
O-sesame git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2 c92efa57-630b-4861-b058-cf58834340f0 2003-01-20 05:58:50 +08:00			`!`
Mixing scheme modified in order to conserve the total charge. The charge is renormalized at nelec after it has been generated from atomic densities. It is also renormalized to nelec after the extrapolation procedure. Added a further check in electrons. rho2zeta modified so that the forward and backward procedure are exactly one the opposite of the other. Fixed a bug in update_pot : the wavefinctions were not extrapolated in parallel runs. Global cleanup of these routines: level 1 blas removed. C.S. git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1519 c92efa57-630b-4861-b058-cf58834340f0 2004-12-21 23:28:01 +08:00			`! Copyright (C) 2001-2004 PWSCF group`
O-sesame git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2 c92efa57-630b-4861-b058-cf58834340f0 2003-01-20 05:58:50 +08:00			`! 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 .`
			`!`
Mixing scheme modified in order to conserve the total charge. The charge is renormalized at nelec after it has been generated from atomic densities. It is also renormalized to nelec after the extrapolation procedure. Added a further check in electrons. rho2zeta modified so that the forward and backward procedure are exactly one the opposite of the other. Fixed a bug in update_pot : the wavefinctions were not extrapolated in parallel runs. Global cleanup of these routines: level 1 blas removed. C.S. git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1519 c92efa57-630b-4861-b058-cf58834340f0 2004-12-21 23:28:01 +08:00			`!----------------------------------------------------------------------------`
			`SUBROUTINE rho2zeta( rho, rho_core, nrxx, nspin, iop )`
			`!---------------------------------------------------------------------------`
O-sesame git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2 c92efa57-630b-4861-b058-cf58834340f0 2003-01-20 05:58:50 +08:00			`!`
Mixing scheme modified in order to conserve the total charge. The charge is renormalized at nelec after it has been generated from atomic densities. It is also renormalized to nelec after the extrapolation procedure. Added a further check in electrons. rho2zeta modified so that the forward and backward procedure are exactly one the opposite of the other. Fixed a bug in update_pot : the wavefinctions were not extrapolated in parallel runs. Global cleanup of these routines: level 1 blas removed. C.S. git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1519 c92efa57-630b-4861-b058-cf58834340f0 2004-12-21 23:28:01 +08:00			`! ... if ( iopi == 1 ) transform the spin up spin down charge density`
			`! ... rho(*,is) into :`
			`!`
			`! ... rho(*,1) = ( rho_up + rho_dw ) and`
			`! ... rho(*,2) = ( rho_up - rho_dw ) / rho_tot = zeta`
			`!`
			`! ... if ( iopi == -1) do the opposit transformation`
			`!`
			`USE constants, ONLY : eps32`
			`USE io_global, ONLY : stdout`
			`USE kinds, ONLY : DP`
			`!`
			`IMPLICIT NONE`
			`!`
			`INTEGER :: iop, nspin, nrxx, ir`
			`! the input option`
			`! the number of spin polarizations`
			`! the fft grid dimension`
			`! the counter for fft grid`
dbl => DP (defined as previously dbl was) syntax for declarations: real(DP), without "kind=" git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2135 c92efa57-630b-4861-b058-cf58834340f0 2005-08-28 22:09:42 +08:00			`REAL(DP) :: rho(nrxx,nspin), rho_core(nrxx), &`
Mixing scheme modified in order to conserve the total charge. The charge is renormalized at nelec after it has been generated from atomic densities. It is also renormalized to nelec after the extrapolation procedure. Added a further check in electrons. rho2zeta modified so that the forward and backward procedure are exactly one the opposite of the other. Fixed a bug in update_pot : the wavefinctions were not extrapolated in parallel runs. Global cleanup of these routines: level 1 blas removed. C.S. git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@1519 c92efa57-630b-4861-b058-cf58834340f0 2004-12-21 23:28:01 +08:00			`rho_up, rho_dw, zeta, rhox`
			`! the scf charge density`
			`! the core charge density`
			`! auxiliary variable for rho up`
			`! auxiliary variable for rho dw`
			`! auxiliary variable for zeta`
			`! auxiliary variable for total rho`
			`!`
			`!`
			`IF ( nspin == 1 ) RETURN`
			`!`
			`IF ( iop == 1 ) THEN`
			`!`
			`DO ir = 1, nrxx`
			`!`
			`rhox = rho(ir,1) + rho(ir,2) + rho_core(ir)`
			`!`
			`IF ( rhox > eps32 ) THEN`
			`!`
			`zeta = ( rho(ir,1) - rho(ir,2) ) / rhox`
			`!`
			`ELSE`
			`!`
			`zeta = 0.D0`
			`!`
			`END IF`
			`!`
			`rho(ir,1) = rho(ir,1) + rho(ir,2)`
			`rho(ir,2) = zeta`
			`!`
			`END DO`
			`!`
			`ELSE IF ( iop == - 1 ) THEN`
			`!`
			`DO ir = 1, nrxx`
			`!`
			`rhox = rho(ir,1) + rho_core(ir)`
			`!`
			`rho_up = 0.5D0 * ( rho(ir,1) + rho(ir,2) * rhox )`
			`rho_dw = 0.5D0 * ( rho(ir,1) - rho(ir,2) * rhox )`
			`!`
			`rho(ir,1) = rho_up`
			`rho(ir,2) = rho_dw`
			`!`
			`END DO`
			`!`
			`ELSE`
			`!`
			`WRITE( stdout , '(5X,"iop = ",I5)' ) iop`
			`!`
			`CALL errore( 'mag2zeta', 'wrong iop', 1 )`
			`!`
			`END IF`
			`!`
			`RETURN`
			`!`
			`END SUBROUTINE rho2zeta`