./41_geometry/fcart2fred.F90

ABINIT/fcart2fred

ABINIT/fcart2fred [ Functions ]

NAME

 fcart2fred

FUNCTION

 Convert cartesian forces into reduced forces

 Copyright (C) 1998-2017 ABINIT group (DCA, XG, GMR, FJ, MT)
 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

  fcart(3,natom)=forces in cartesian coordinates (Ha/Bohr)
  natom=Number of atoms in the unitary cell
  rprimd(3,3)=dimensional primitive

OUTPUT

  fred(3,natom)=symmetrized grtn = d(etotal)/d(xred)

SIDE EFFECTS

NOTES

    Unlike fred, fcart has been corrected by enforcing
    the translational symmetry, namely that the sum of force
    on all atoms is zero.

PARENTS

      gstateimg,m_abihist,m_effective_potential,m_mep,mover,prec_simple
      pred_bfgs,pred_delocint,pred_lbfgs,pred_verlet,prtxfase

CHILDREN

SOURCE

40 #if defined HAVE_CONFIG_H
41 #include "config.h"
42 #endif
43 
44 #include "abi_common.h"
45 
46 
47 subroutine fcart2fred(fcart,fred,rprimd,natom)
48 
49  use defs_basis
50  use m_profiling_abi
51 
52 !This section has been created automatically by the script Abilint (TD).
53 !Do not modify the following lines by hand.
54 #undef ABI_FUNC
55 #define ABI_FUNC 'fcart2fred'
56 !End of the abilint section
57 
58  implicit none
59 
60 !Arguments ------------------------------------
61 !scalars
62  integer,intent(in) :: natom
63 !arrays
64  real(dp),intent(in) :: fcart(3,natom)
65  real(dp),intent(out) :: fred(3,natom)
66  real(dp),intent(in) :: rprimd(3,3)
67 
68 !Local variables-------------------------------
69 !scalars
70  integer :: iatom,mu
71 
72 ! *************************************************************************
73 
74 !MT, april 2012: the coding was not consistent with fred2fcart
75  do iatom=1,natom
76    do mu=1,3
77      fred(mu,iatom)= - (rprimd(1,mu)*fcart(1,iatom)+&
78 &     rprimd(2,mu)*fcart(2,iatom)+&
79 &     rprimd(3,mu)*fcart(3,iatom))
80    end do
81  end do
82 
83 !Previous version
84 !do iatom=1,natom
85 !do mu=1,3
86 !fred(mu,iatom)= - (rprimd(mu,1)*fcart(1,iatom)+&
87 !&     rprimd(mu,2)*fcart(2,iatom)+&
88 !&     rprimd(mu,3)*fcart(3,iatom))
89 !end do
90 !end do
91 
92 end subroutine fcart2fred

TABLE OF CONTENTS

ABINIT/fcart2fred [ Functions ]