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lammps/src/USER-OMP/pair_vashishta_omp.cpp
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pair_vashishta_omp.cpp
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/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
This software is distributed under the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing author: Axel Kohlmeyer (Temple U)
------------------------------------------------------------------------- */
#include <math.h>
#include "pair_vashishta_omp.h"
#include "atom.h"
#include "comm.h"
#include "force.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "suffix.h"
using namespace LAMMPS_NS;
/* ---------------------------------------------------------------------- */
PairVashishtaOMP::PairVashishtaOMP(LAMMPS *lmp) :
PairVashishta(lmp), ThrOMP(lmp, THR_PAIR)
{
suffix_flag |= Suffix::OMP;
respa_enable = 0;
}
/* ---------------------------------------------------------------------- */
void PairVashishtaOMP::compute(int eflag, int vflag)
{
if (eflag || vflag) {
ev_setup(eflag,vflag);
} else evflag = vflag_fdotr = 0;
const int nall = atom->nlocal + atom->nghost;
const int nthreads = comm->nthreads;
const int inum = list->inum;
#if defined(_OPENMP)
#pragma omp parallel default(none) shared(eflag,vflag)
#endif
{
int ifrom, ito, tid;
loop_setup_thr(ifrom, ito, tid, inum, nthreads);
ThrData *thr = fix->get_thr(tid);
thr->timer(Timer::START);
ev_setup_thr(eflag, vflag, nall, eatom, vatom, thr);
if (evflag) {
if (eflag) {
eval<1,1>(ifrom, ito, thr);
} else {
eval<1,0>(ifrom, ito, thr);
}
} else eval<0,0>(ifrom, ito, thr);
thr->timer(Timer::PAIR);
reduce_thr(this, eflag, vflag, thr);
} // end of omp parallel region
}
template <int EVFLAG, int EFLAG>
void PairVashishtaOMP::eval(int iifrom, int iito, ThrData * const thr)
{
int i,j,k,ii,jj,kk,jnum,jnumm1;
tagint itag,jtag;
int itype,jtype,ktype,ijparam,ikparam,ijkparam;
double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
double rsq,rsq1,rsq2;
double delr1[3],delr2[3],fj[3],fk[3];
int *ilist,*jlist,*numneigh,**firstneigh;
evdwl = 0.0;
const dbl3_t * _noalias const x = (dbl3_t *) atom->x[0];
dbl3_t * _noalias const f = (dbl3_t *) thr->get_f()[0];
const tagint * _noalias const tag = atom->tag;
const int * _noalias const type = atom->type;
const int nlocal = atom->nlocal;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
double fxtmp,fytmp,fztmp;
// loop over full neighbor list of my atoms
for (ii = iifrom; ii < iito; ++ii) {
i = ilist[ii];
itag = tag[i];
itype = map[type[i]];
xtmp = x[i].x;
ytmp = x[i].y;
ztmp = x[i].z;
fxtmp = fytmp = fztmp = 0.0;
// two-body interactions, skip half of them
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
j &= NEIGHMASK;
jtag = tag[j];
if (itag > jtag) {
if ((itag+jtag) % 2 == 0) continue;
} else if (itag < jtag) {
if ((itag+jtag) % 2 == 1) continue;
} else {
if (x[j].z < ztmp) continue;
if (x[j].z == ztmp && x[j].y < ytmp) continue;
if (x[j].z == ztmp && x[j].y == ytmp && x[j].x < xtmp) continue;
}
jtype = map[type[j]];
delx = xtmp - x[j].x;
dely = ytmp - x[j].y;
delz = ztmp - x[j].z;
rsq = delx*delx + dely*dely + delz*delz;
ijparam = elem2param[itype][jtype][jtype];
if (rsq >= params[ijparam].cutsq) continue;
twobody(&params[ijparam],rsq,fpair,EFLAG,evdwl, useTable);
fxtmp += delx*fpair;
fytmp += dely*fpair;
fztmp += delz*fpair;
f[j].x -= delx*fpair;
f[j].y -= dely*fpair;
f[j].z -= delz*fpair;
if (EVFLAG) ev_tally_thr(this,i,j,nlocal,/* newton_pair */ 1,
evdwl,0.0,fpair,delx,dely,delz,thr);
}
jnumm1 = jnum - 1;
for (jj = 0; jj < jnumm1; jj++) {
j = jlist[jj];
j &= NEIGHMASK;
jtype = map[type[j]];
ijparam = elem2param[itype][jtype][jtype];
delr1[0] = x[j].x - xtmp;
delr1[1] = x[j].y - ytmp;
delr1[2] = x[j].z - ztmp;
rsq1 = delr1[0]*delr1[0] + delr1[1]*delr1[1] + delr1[2]*delr1[2];
if (rsq1 >= params[ijparam].cutsq2) continue;
double fjxtmp,fjytmp,fjztmp;
fjxtmp = fjytmp = fjztmp = 0.0;
for (kk = jj+1; kk < jnum; kk++) {
k = jlist[kk];
k &= NEIGHMASK;
ktype = map[type[k]];
ikparam = elem2param[itype][ktype][ktype];
ijkparam = elem2param[itype][jtype][ktype];
delr2[0] = x[k].x - xtmp;
delr2[1] = x[k].y - ytmp;
delr2[2] = x[k].z - ztmp;
rsq2 = delr2[0]*delr2[0] + delr2[1]*delr2[1] + delr2[2]*delr2[2];
if (rsq2 >= params[ikparam].cutsq2) continue;
threebody(&params[ijparam],&params[ikparam],&params[ijkparam],
rsq1,rsq2,delr1,delr2,fj,fk,EFLAG,evdwl);
fxtmp -= fj[0] + fk[0];
fytmp -= fj[1] + fk[1];
fztmp -= fj[2] + fk[2];
fjxtmp += fj[0];
fjytmp += fj[1];
fjztmp += fj[2];
f[k].x += fk[0];
f[k].y += fk[1];
f[k].z += fk[2];
if (EVFLAG) ev_tally3_thr(this,i,j,k,evdwl,0.0,fj,fk,delr1,delr2,thr);
}
f[j].x += fjxtmp;
f[j].y += fjytmp;
f[j].z += fjztmp;
}
f[i].x += fxtmp;
f[i].y += fytmp;
f[i].z += fztmp;
}
}
/* ---------------------------------------------------------------------- */
double PairVashishtaOMP::memory_usage()
{
double bytes = memory_usage_thr();
bytes += PairVashishta::memory_usage();
return bytes;
}
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