./62_poisson/psolver

ABINIT/Psolver_hartree

ABINIT/Psolver_hartree [ Functions ]

NAME

 Psolver_hartree

FUNCTION

 Given rho(r), compute Hartree potential considering the system as
 an isolated one. This potential is obtained from the convolution
 of 1/r and rho(r), treated in Fourier space. This method is a wrapper around
 Psolver() developped for BigDFT.
 It does not compute the xc energy nor potential. See psolver_rhohxc() to do it.
 WARNING : the XC energy and potential computation capability has been
 for spin-polarized case, as everything is done as if nspden=1

 Copyright (C) 1998-2018 ABINIT group (DCA, XG, GMR).
 This file is distributed under the terms of the
 GNU General Public License, see ~abinit/COPYING
 or http://www.gnu.org/copyleft/gpl.txt .
 For the initials of contributors, see ~abinit/doc/developers/contributors.txt .

INPUTS

  dtset <type(dataset_type)>=all input variables in this dataset
  mpi_enreg=MPI-parallelisation information.
  rhor(nfft,nspden)=electron density in real space in electrons/bohr**3

OUTPUT

  enhartr=returned Hartree energy (hartree).
  vhartr(nfft)=Hartree potential.

 NOTE
  In PSolver, with nspden == 2, rhor(:,1) = density up and
                                rhor(:,2) = density down.
  But in ABINIT (dtset%usewvl != 1) rhor(:,1) = total density and
                                    rhor(:,2) = density up .
  In ABINIT (dtset%usewvl != 1), the same convention is used as in PSolver.

PARENTS

      mklocl_realspace,nres2vres

CHILDREN

      h_potential,psolver_kernel,wrtout

SOURCE

 46 #if defined HAVE_CONFIG_H
 47 #include "config.h"
 48 #endif
 49 
 50 #include "abi_common.h"
 51 
 52 
 53 subroutine psolver_hartree(enhartr, hgrid, icoulomb, me, mpi_comm, nfft, ngfft, nproc, &
 54      & nscforder, nspden, rhor, vhartr, usewvl)
 55 
 56  use defs_basis
 57  use m_errors
 58  use m_profiling_abi
 59 #if defined HAVE_BIGDFT
 60  use BigDFT_API,     only : coulomb_operator
 61  use poisson_solver, only : H_potential
 62 #endif
 63 
 64 !This section has been created automatically by the script Abilint (TD).
 65 !Do not modify the following lines by hand.
 66 #undef ABI_FUNC
 67 #define ABI_FUNC 'psolver_hartree'
 68  use interfaces_14_hidewrite
 69  use interfaces_62_poisson, except_this_one => psolver_hartree
 70 !End of the abilint section
 71 
 72   implicit none
 73 
 74   !Arguments ------------------------------------
 75   !scalars
 76   integer, intent(in)           :: nfft, nspden, icoulomb, usewvl, mpi_comm, me, nproc, nscforder
 77   real(dp), intent(out)         :: enhartr
 78   !arrays
 79   integer, intent(in)    :: ngfft(3)
 80   real(dp),intent(in)    :: hgrid(3)
 81   real(dp),intent(in)    :: rhor(nfft,nspden)
 82   real(dp),intent(out)   :: vhartr(nfft)
 83 
 84   !Local variables-------------------------------
 85 #if defined HAVE_BIGDFT
 86   !scalars
 87   character(len=500) :: message
 88   character(len = 1) :: datacode, bndcode
 89   !arrays
 90   real(dp), dimension(1) :: pot_ion_dummy
 91   type(coulomb_operator):: kernel
 92 #endif
 93 
 94 ! *********************************************************************
 95 
 96 #if defined HAVE_BIGDFT
 97 
 98  if (icoulomb == 0) then
 99 !  The kernel is built with 'P'eriodic boundary counditions.
100    bndcode = 'P'
101  else if (icoulomb == 1) then
102 !  The kernel is built with 'F'ree boundary counditions.
103    bndcode = 'F'
104  else if (icoulomb == 2) then
105 !  The kernel is built with 'S'urface boundary counditions.
106    bndcode = 'S'
107  end if
108 
109  if(nspden > 2 .and. usewvl/=0 )then
110    write(message, '(a,a,a,i0)' )&
111 &   'Only non-spin-polarised or collinear spin is allowed for wavelets,',ch10,&
112 &   'while the argument nspden = ', nspden
113    MSG_BUG(message)
114  end if
115 
116 !We do the computation.
117  write(message, "(A,A,A,3I6)") "Psolver_hartree(): compute potential (Vhartree)...", ch10, &
118 & " | dimension:", ngfft(1:3)
119  call wrtout(std_out, message,'COLL')
120 
121  if (usewvl == 0) then
122    vhartr(:)  = rhor(:, 1)
123 
124    datacode = 'G'
125 !  This may not work with MPI in the planewave code...
126  else
127    if(nspden==1)vhartr(:)  = rhor(:, 1)
128    if(nspden==2)vhartr(:)  = rhor(:, 1) + rhor(:, 2)
129 !  The data are 'D'istributed in the wavelet case or 'G'lobal otherwise.
130    if (nproc > 1) then
131      datacode = 'D'
132    else
133      datacode = 'G'
134    end if
135  end if
136 
137 !We get the kernel.
138  call psolver_kernel( hgrid, 2, icoulomb, me, kernel, mpi_comm, ngfft, nproc, nscforder)
139 
140 
141 !We attack PSolver with the total density contained in vhartr.
142 !This is also valid for spin-polarized (collinear and non-collinear)
143 !systems. Thus we enter nspden (last arg of PSolver) as being 1.
144 !Warning : enxc and evxc are meaningless.
145 ! call psolver(bndcode, datacode, me, nproc, ngfft(1), ngfft(2), ngfft(3),&
146 !& 0, hgrid(1), hgrid(2), hgrid(3), vhartr, kernel%co%kernel, pot_ion_dummy, &
147 !& enhartr, enxc, evxc, 0.d0, .false., 1)
148 
149  call H_potential(datacode,kernel,vhartr,pot_ion_dummy,&
150 & enhartr,zero,.false.)
151 
152 
153 #else
154  BIGDFT_NOTENABLED_ERROR() 
155  if (.false.) write(std_out,*)  nfft,nspden,icoulomb,usewvl,mpi_comm,me,nproc,nscforder,enhartr,&
156 & ngfft(1),hgrid(1),rhor(1,1),vhartr(1)
157 #endif
158 
159 end subroutine psolver_hartree

TABLE OF CONTENTS

ABINIT/Psolver_hartree [ Functions ]