TABLE OF CONTENTS
ABINIT/m_predict_string [ Modules ]
NAME
m_predict_string
FUNCTION
COPYRIGHT
Copyright (C) 2009-2018 ABINIT group (XG,ARom,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 .
PARENTS
CHILDREN
SOURCE
21 #if defined HAVE_CONFIG_H 22 #include "config.h" 23 #endif 24 25 #include "abi_common.h" 26 27 module m_predict_string 28 29 use defs_basis 30 use defs_abitypes 31 use m_abicore 32 use m_splines 33 use m_mep 34 use m_errors 35 use m_xmpi 36 37 use m_results_img, only : results_img_type, gather_array_img, get_geometry_img 38 39 implicit none 40 41 private
ABINIT/predict_string [ Functions ]
NAME
predict_string
FUNCTION
Given the past history of images, predict the new set of images using String Method. The changes on the geometry and others are predicted by rescaling the path No change of acell, rprim and vel at present.
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.
This is quite useful when ground states of the A and B states is known
mpi_enreg=MPI-parallelisation information
natom=dimension of vel_timimage and xred_timimage
ndynimage=number of dynamical images
nimage=number of images (on current proc)
nimage_tot=total number of images
ntimimage_stored=number of time steps stored in the history
OUTPUT
SIDE EFFECTS
mep_param=several parameters for Minimal Energy Path (MEP) search
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
gather_array_img,get_geometry_img,mep_rk4,mep_steepest,spline,splint xmpi_bcast
SOURCE
104 subroutine predict_string(itimimage,itimimage_eff,list_dynimage,mep_param,mpi_enreg,natom,& 105 & ndynimage,nimage,nimage_tot,ntimimage_stored,results_img) 106 107 108 !This section has been created automatically by the script Abilint (TD). 109 !Do not modify the following lines by hand. 110 #undef ABI_FUNC 111 #define ABI_FUNC 'predict_string' 112 !End of the abilint section 113 114 implicit none 115 116 !Arguments ------------------------------------ 117 !scalars 118 integer,intent(in) :: itimimage,itimimage_eff,natom,ndynimage 119 integer,intent(in) :: nimage,nimage_tot,ntimimage_stored 120 type(mep_type),intent(inout) :: mep_param 121 type(MPI_type),intent(in) :: mpi_enreg 122 !arrays 123 integer,intent(in) :: list_dynimage(ndynimage) 124 type(results_img_type) :: results_img(nimage,ntimimage_stored) 125 126 !Local variables------------------------------- 127 !scalars 128 integer :: idynimage,ierr,ii,iimage,iatom,next_itimimage 129 real(dp) :: emax,emin,step 130 !arrays 131 real(dp),allocatable :: buffer(:,:),buffer_all(:,:) 132 real(dp),allocatable :: darc(:),dimage(:),fcart(:,:,:),rprimd(:,:,:),vect(:,:),wimage(:) 133 real(dp),allocatable :: x(:),y(:),z(:),x2(:),y2(:),z2(:) 134 real(dp),allocatable :: xout(:),yout(:),zout(:) 135 real(dp),allocatable,target :: etotal(:),xcart(:,:,:),xred(:,:,:) 136 real(dp),pointer :: etotal_all(:),xcart_all(:,:,:),xred_all(:,:,:) 137 138 ! ************************************************************************* 139 140 ABI_ALLOCATE(xred,(3,natom,nimage)) 141 142 !Parallelism over images: only one process per image of the cell 143 if (mpi_enreg%me_cell==0) then 144 145 ! Retrieve positions and forces 146 ABI_ALLOCATE(etotal,(nimage)) 147 ABI_ALLOCATE(xcart,(3,natom,nimage)) 148 ABI_ALLOCATE(fcart,(3,natom,nimage)) 149 ABI_ALLOCATE(rprimd,(3,3,nimage)) 150 call get_geometry_img(etotal,natom,nimage,results_img(:,itimimage_eff),& 151 & fcart,rprimd,xcart,xred) 152 153 ! EVOLUTION STEP 154 ! =============================================== 155 156 ! Compute new atomic positions in each cell 157 if (mep_param%mep_solver==0) then ! Steepest-descent 158 call mep_steepest(fcart,list_dynimage,mep_param,natom,ndynimage,nimage,rprimd,xcart,xred) 159 else if (mep_param%mep_solver==4) then ! 4th-order Runge-Kutta 160 call mep_rk4(fcart,itimimage,list_dynimage,mep_param,natom,ndynimage,nimage,rprimd,xcart,xred) 161 else 162 MSG_BUG("Inconsistent solver !") 163 end if 164 165 ! REPARAMETRIZATION STEP 166 ! =============================================== 167 168 ! No reparametrization step in case of Runge-Kutta and mod(istep,4)>0 169 if (mep_param%mep_solver/=4.or.mod(itimimage,4)==0) then 170 171 ! Parallelism: gather data of all images 172 if (mpi_enreg%paral_img==1) then 173 ABI_ALLOCATE(buffer,(6*natom+1,nimage)) 174 ABI_ALLOCATE(buffer_all,(6*natom+1,nimage_tot)) 175 ABI_ALLOCATE(xred_all,(3,natom,nimage_tot)) 176 ABI_ALLOCATE(xcart_all,(3,natom,nimage_tot)) 177 ABI_ALLOCATE(etotal_all,(nimage_tot)) 178 buffer=zero;ii=0 179 buffer(ii+1:ii+3*natom,1:nimage)=reshape(xred ,(/3*natom,nimage/));ii=3*natom 180 buffer(ii+1:ii+3*natom,1:nimage)=reshape(xcart,(/3*natom,nimage/));ii=6*natom 181 buffer(ii+1 ,1:nimage)=etotal(1:nimage);ii=0 182 call gather_array_img(buffer,buffer_all,mpi_enreg,allgather=.true.) 183 xred_all(:,:,:) =reshape(buffer_all(ii+1:ii+3*natom,1:nimage_tot),(/3,natom,nimage_tot/));ii=3*natom 184 xcart_all(:,:,:)=reshape(buffer_all(ii+1:ii+3*natom,1:nimage_tot),(/3,natom,nimage_tot/));ii=6*natom 185 etotal_all(:)=buffer_all(ii+1,1:nimage_tot);ii=0 186 ABI_DEALLOCATE(buffer) 187 ABI_DEALLOCATE(buffer_all) 188 else 189 xred_all => xred 190 xcart_all => xcart 191 etotal_all => etotal 192 end if 193 194 ! dimage is the distance between two images 195 ! darc is the parametrization on the string 196 ! wimage is the weight 197 ABI_ALLOCATE(darc,(nimage_tot)) 198 ABI_ALLOCATE(dimage,(nimage_tot)) 199 ABI_ALLOCATE(wimage,(nimage_tot)) 200 201 ! === Weights for equal arc length 202 if (mep_param%string_algo/=2) then 203 wimage(:)=one 204 205 ! === Weights for energy-weight arc length 206 else 207 emin=min(etotal_all(1),etotal_all(nimage_tot)) 208 emax=maxval(etotal_all(:)) 209 wimage(1)=one 210 do iimage=2,nimage_tot 211 wimage(iimage)=exp((half*(etotal_all(iimage)+etotal_all(iimage-1))-emin)/(emax-emin)) 212 end do 213 end if 214 215 ! The distance between images is calculated 216 ! and normalized to a string length of 1.0 217 dimage=zero 218 ABI_ALLOCATE(vect,(3,natom)) 219 do iimage=2,nimage_tot 220 dimage(iimage)=dimage(iimage-1) 221 ! MT april 2012: distance must be computed with cartesian coordinates 222 ! vect(:,:)=xred_all(:,:,iimage)-xred_all(:,:,iimage-1) 223 vect(:,:)=xcart_all(:,:,iimage)-xcart_all(:,:,iimage-1) 224 dimage(iimage)=dimage(iimage)+wimage(iimage)*mep_img_norm(vect) 225 end do 226 dimage(:)=dimage(:)/dimage(nimage_tot) 227 ABI_DEALLOCATE(vect) 228 229 ! Arc lengths 230 darc(1)=zero 231 step=one/dble(nimage_tot-1) 232 do iimage=2,nimage_tot 233 darc(iimage)=darc(iimage-1)+step 234 end do 235 236 ! New image coordinates are calculated and such that now the mesh is uniform 237 ABI_ALLOCATE(x,(nimage_tot)) 238 ABI_ALLOCATE(y,(nimage_tot)) 239 ABI_ALLOCATE(z,(nimage_tot)) 240 ABI_ALLOCATE(x2,(nimage_tot)) 241 ABI_ALLOCATE(y2,(nimage_tot)) 242 ABI_ALLOCATE(z2,(nimage_tot)) 243 ABI_ALLOCATE(xout,(nimage_tot)) 244 ABI_ALLOCATE(yout,(nimage_tot)) 245 ABI_ALLOCATE(zout,(nimage_tot)) 246 do iatom=1,natom 247 do iimage=1,nimage_tot 248 x(iimage)=xred_all(1,iatom,iimage) 249 y(iimage)=xred_all(2,iatom,iimage) 250 z(iimage)=xred_all(3,iatom,iimage) 251 end do 252 call spline(dimage,x,nimage_tot,greatest_real,greatest_real,x2) 253 call spline(dimage,y,nimage_tot,greatest_real,greatest_real,y2) 254 call spline(dimage,z,nimage_tot,greatest_real,greatest_real,z2) 255 call splint(nimage_tot,dimage,x,x2,nimage_tot,darc,xout) 256 call splint(nimage_tot,dimage,y,y2,nimage_tot,darc,yout) 257 call splint(nimage_tot,dimage,z,z2,nimage_tot,darc,zout) 258 ! After a spline, new image coordinate for that particular 259 ! atom are generated only if they are dynamical 260 do idynimage=1,ndynimage 261 iimage=list_dynimage(idynimage) 262 ii=mpi_enreg%my_imgtab(iimage) 263 xred(1,iatom,iimage)=xout(ii) 264 xred(2,iatom,iimage)=yout(ii) 265 xred(3,iatom,iimage)=zout(ii) 266 end do 267 end do ! iatom 268 269 ! Free memory 270 ABI_DEALLOCATE(x) 271 ABI_DEALLOCATE(y) 272 ABI_DEALLOCATE(z) 273 ABI_DEALLOCATE(x2) 274 ABI_DEALLOCATE(y2) 275 ABI_DEALLOCATE(z2) 276 ABI_DEALLOCATE(xout) 277 ABI_DEALLOCATE(yout) 278 ABI_DEALLOCATE(zout) 279 ABI_DEALLOCATE(darc) 280 ABI_DEALLOCATE(dimage) 281 ABI_DEALLOCATE(wimage) 282 if (mpi_enreg%paral_img==1) then 283 ABI_DEALLOCATE(xred_all) 284 ABI_DEALLOCATE(xcart_all) 285 ABI_DEALLOCATE(etotal_all) 286 end if 287 288 end if ! Reparametrization 289 290 ! =============================================== 291 292 ABI_DEALLOCATE(etotal) 293 ABI_DEALLOCATE(xcart) 294 ABI_DEALLOCATE(fcart) 295 ABI_DEALLOCATE(rprimd) 296 end if ! mpi_enreg%me_cell==0 297 298 !Store acell, rprim, xred and vel for the new iteration 299 call xmpi_bcast(xred,0,mpi_enreg%comm_cell,ierr) 300 next_itimimage=itimimage_eff+1 301 if (next_itimimage>ntimimage_stored) next_itimimage=1 302 do iimage=1,nimage 303 results_img(iimage,next_itimimage)%xred(:,:) =xred(:,:,iimage) 304 results_img(iimage,next_itimimage)%acell(:) =results_img(iimage,itimimage_eff)%acell(:) 305 results_img(iimage,next_itimimage)%rprim(:,:) =results_img(iimage,itimimage_eff)%rprim(:,:) 306 results_img(iimage,next_itimimage)%vel(:,:) =results_img(iimage,itimimage_eff)%vel(:,:) 307 results_img(iimage,next_itimimage)%vel_cell(:,:)=results_img(iimage,itimimage_eff)%vel_cell(:,:) 308 end do 309 ABI_DEALLOCATE(xred) 310 311 end subroutine predict_string