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ABINIT/predict_steepest [ Functions ]

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NAME

 predict_steepest

FUNCTION

 Given the past history of images, predict the new set of images.
 Here, simple steepest descent algorithm, based on the value of the forces on the current timimage step.
 No change of acell, rprim and vel at present.

COPYRIGHT

 Copyright (C) 2009-2018 ABINIT group (XG)
 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

 itimimage=time index for image propagation (itimimage+1 is to be predicted here)
 itimimage_eff=time index in the history
 list_dynimage(nimage)=list of dynamical images. The non-dynamical ones will not change.
       Example : in the NEB of string method, one expect the two end images to be fixed.
 mep_param=several parameters for Minimal Energy Path (MEP) search
 natom=dimension of vel_timimage and xred_timimage
 ndynimage=number of dynamical images
 nimage=number of images
 ntimimage_stored=number of time steps stored in the history

OUTPUT

SIDE EFFECTS

 results_img(ntimimage_stored,nimage)=datastructure that holds the history of previous computations.
   results_img(:,:)%acell(3)
    at input, history of the values of acell for all images
    at output, the predicted values of acell for all images
   results_img(:,:)%results_gs
    at input, history of the values of energies and forces for all images
   results_img(:,:)%rprim(3,3)
    at input, history of the values of rprim for all images
    at output, the predicted values of rprim for all images
   results_img(:,:)%vel(3,natom)
    at input, history of the values of vel for all images
    at output, the predicted values of vel for all images
   results_img(:,:)%vel_cell(3,3)
    at input, history of the values of vel_cell for all images
    at output, the predicted values of vel_cell for all images
   results_img(:,:)%xred(3,natom)
    at input, history of the values of xred for all images
    at output, the predicted values of xred for all images

PARENTS

      predictimg

CHILDREN

      get_geometry_img,mep_steepest

SOURCE

 59 #if defined HAVE_CONFIG_H
 60 #include "config.h"
 61 #endif
 62 
 63 #include "abi_common.h"
 64 
 65 subroutine predict_steepest(itimimage,itimimage_eff,list_dynimage,mep_param,natom,&
 66 &                           ndynimage,nimage,ntimimage_stored,results_img)
 67 
 68  use m_profiling_abi
 69 
 70  use defs_basis
 71  use m_results_img, only : results_img_type,get_geometry_img
 72  use m_mep
 73 
 74 !This section has been created automatically by the script Abilint (TD).
 75 !Do not modify the following lines by hand.
 76 #undef ABI_FUNC
 77 #define ABI_FUNC 'predict_steepest'
 78 !End of the abilint section
 79 
 80  implicit none
 81 
 82 !Arguments ------------------------------------
 83 !scalars
 84  integer,intent(in) :: itimimage,itimimage_eff,natom,ndynimage
 85  integer,intent(in) :: nimage,ntimimage_stored
 86  type(mep_type),intent(inout) :: mep_param
 87 !arrays
 88  integer,intent(in) :: list_dynimage(ndynimage)
 89  type(results_img_type) :: results_img(nimage,ntimimage_stored)
 90 
 91 !Local variables-------------------------------
 92 !scalars
 93  integer :: iimage,next_itimimage
 94 !arrays
 95  real(dp),allocatable :: etotal(:),fcart(:,:,:),rprimd(:,:,:),xcart(:,:,:),xred(:,:,:)
 96 
 97 ! *************************************************************************
 98 
 99 !Retrieve positions and forces
100  ABI_ALLOCATE(etotal,(nimage))
101  ABI_ALLOCATE(xred,(3,natom,nimage))
102  ABI_ALLOCATE(xcart,(3,natom,nimage))
103  ABI_ALLOCATE(fcart,(3,natom,nimage))
104  ABI_ALLOCATE(rprimd,(3,3,nimage))
105  call get_geometry_img(etotal,natom,nimage,results_img(:,itimimage_eff),&
106 & fcart,rprimd,xcart,xred)
107 
108 !Compute new atomic positions in each cell
109  call mep_steepest(fcart,list_dynimage,mep_param,natom,ndynimage,nimage,rprimd,xcart,xred)
110 
111 !Store acell, rprim, xred and vel for the new iteration
112  next_itimimage=itimimage+1
113  if (next_itimimage>ntimimage_stored) next_itimimage=1
114  do iimage=1,nimage
115    results_img(iimage,next_itimimage)%xred(:,:)    =xred(:,:,iimage)
116    results_img(iimage,next_itimimage)%acell(:)     =results_img(iimage,itimimage_eff)%acell(:)
117    results_img(iimage,next_itimimage)%rprim(:,:)   =results_img(iimage,itimimage_eff)%rprim(:,:)
118    results_img(iimage,next_itimimage)%vel(:,:)     =results_img(iimage,itimimage_eff)%vel(:,:)
119    results_img(iimage,next_itimimage)%vel_cell(:,:)=results_img(iimage,itimimage_eff)%vel_cell(:,:)
120  end do
121 
122  ABI_DEALLOCATE(etotal)
123  ABI_DEALLOCATE(xred)
124  ABI_DEALLOCATE(xcart)
125  ABI_DEALLOCATE(fcart)
126  ABI_DEALLOCATE(rprimd)
127 
128 end subroutine predict_steepest