214 lines
6.9 KiB
C++
214 lines
6.9 KiB
C++
/* ----------------------------------------------------------------------
|
|
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 <cmath>
|
|
#include "pair_lj_charmm_coul_long_soft_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;
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
PairLJCharmmCoulLongSoftOMP::PairLJCharmmCoulLongSoftOMP(LAMMPS *lmp) :
|
|
PairLJCharmmCoulLongSoft(lmp), ThrOMP(lmp, THR_PAIR)
|
|
{
|
|
suffix_flag |= Suffix::OMP;
|
|
respa_enable = 0;
|
|
cut_respa = NULL;
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairLJCharmmCoulLongSoftOMP::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) {
|
|
if (force->newton_pair) eval<1,1,1>(ifrom, ito, thr);
|
|
else eval<1,1,0>(ifrom, ito, thr);
|
|
} else {
|
|
if (force->newton_pair) eval<1,0,1>(ifrom, ito, thr);
|
|
else eval<1,0,0>(ifrom, ito, thr);
|
|
}
|
|
} else {
|
|
if (force->newton_pair) eval<0,0,1>(ifrom, ito, thr);
|
|
else eval<0,0,0>(ifrom, ito, thr);
|
|
}
|
|
|
|
thr->timer(Timer::PAIR);
|
|
reduce_thr(this, eflag, vflag, thr);
|
|
} // end of omp parallel region
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
template <int EVFLAG, int EFLAG, int NEWTON_PAIR>
|
|
void PairLJCharmmCoulLongSoftOMP::eval(int iifrom, int iito, ThrData * const thr)
|
|
{
|
|
|
|
const dbl3_t * _noalias const x = (dbl3_t *) atom->x[0];
|
|
dbl3_t * _noalias const f = (dbl3_t *) thr->get_f()[0];
|
|
const double * _noalias const q = atom->q;
|
|
const int * _noalias const type = atom->type;
|
|
const double * _noalias const special_coul = force->special_coul;
|
|
const double * _noalias const special_lj = force->special_lj;
|
|
const double qqrd2e = force->qqrd2e;
|
|
const double inv_denom_lj = 1.0/denom_lj;
|
|
|
|
const int * const ilist = list->ilist;
|
|
const int * const numneigh = list->numneigh;
|
|
const int * const * const firstneigh = list->firstneigh;
|
|
const int nlocal = atom->nlocal;
|
|
|
|
// loop over neighbors of my atoms
|
|
|
|
for (int ii = iifrom; ii < iito; ++ii) {
|
|
|
|
const int i = ilist[ii];
|
|
const int itype = type[i];
|
|
const double qtmp = q[i];
|
|
const double xtmp = x[i].x;
|
|
const double ytmp = x[i].y;
|
|
const double ztmp = x[i].z;
|
|
double fxtmp,fytmp,fztmp;
|
|
fxtmp=fytmp=fztmp=0.0;
|
|
|
|
const int * const jlist = firstneigh[i];
|
|
const int jnum = numneigh[i];
|
|
const double * _noalias const lj1i = lj1[itype];
|
|
const double * _noalias const lj2i = lj2[itype];
|
|
const double * _noalias const lj3i = lj3[itype];
|
|
const double * _noalias const lj4i = lj4[itype];
|
|
const double * _noalias const epsii = epsilon[itype];
|
|
|
|
for (int jj = 0; jj < jnum; jj++) {
|
|
double forcecoul, forcelj, evdwl, ecoul;
|
|
forcecoul = forcelj = evdwl = ecoul = 0.0;
|
|
|
|
const int sbindex = sbmask(jlist[jj]);
|
|
const int j = jlist[jj] & NEIGHMASK;
|
|
|
|
const double delx = xtmp - x[j].x;
|
|
const double dely = ytmp - x[j].y;
|
|
const double delz = ztmp - x[j].z;
|
|
const double rsq = delx*delx + dely*dely + delz*delz;
|
|
const int jtype = type[j];
|
|
|
|
if (rsq < cutsq[itype][jtype]) {
|
|
|
|
if (rsq < cut_coulsq) {
|
|
const double A1 = 0.254829592;
|
|
const double A2 = -0.284496736;
|
|
const double A3 = 1.421413741;
|
|
const double A4 = -1.453152027;
|
|
const double A5 = 1.061405429;
|
|
const double EWALD_F = 1.12837917;
|
|
const double INV_EWALD_P = 1.0/0.3275911;
|
|
|
|
const double r = sqrt(rsq);
|
|
const double grij = g_ewald * r;
|
|
const double expm2 = exp(-grij*grij);
|
|
const double t = INV_EWALD_P / (INV_EWALD_P + grij);
|
|
const double erfc = t * (A1+t*(A2+t*(A3+t*(A4+t*A5)))) * expm2;
|
|
const double denc = sqrt(lj4i[jtype] + rsq);
|
|
const double prefactor = qqrd2e * lj1i[jtype] * qtmp*q[j] / (denc*denc*denc);
|
|
|
|
forcecoul = prefactor * (erfc + EWALD_F*grij*expm2);
|
|
if (EFLAG) ecoul = prefactor*erfc*denc*denc;
|
|
|
|
if (sbindex) {
|
|
const double adjust = (1.0-special_coul[sbindex])*prefactor;
|
|
forcecoul -= adjust;
|
|
if (EFLAG) ecoul -= adjust*denc*denc;
|
|
}
|
|
}
|
|
|
|
if (rsq < cut_ljsq) {
|
|
const double r4sig6 = rsq*rsq / lj2i[jtype];
|
|
const double denlj = lj3i[jtype] + rsq*r4sig6;
|
|
forcelj = lj1i[jtype] * epsii[jtype] *
|
|
(48.0*r4sig6/(denlj*denlj*denlj) - 24.0*r4sig6/(denlj*denlj));
|
|
const double philj = lj1i[jtype] * 4.0 * epsii[jtype]
|
|
* (1.0/(denlj*denlj) - 1.0/denlj);
|
|
if (EFLAG) evdwl = philj;
|
|
|
|
if (rsq > cut_lj_innersq) {
|
|
const double drsq = cut_ljsq - rsq;
|
|
const double cut2 = (rsq - cut_lj_innersq) * drsq;
|
|
const double switch1 = drsq * (drsq*drsq + 3.0*cut2) * inv_denom_lj;
|
|
const double switch2 = 12.0 * cut2 * inv_denom_lj;
|
|
forcelj = forcelj*switch1 + philj*switch2;
|
|
if (EFLAG) evdwl = philj*switch1;
|
|
}
|
|
|
|
if (sbindex) {
|
|
const double factor_lj = special_lj[sbindex];
|
|
forcelj *= factor_lj;
|
|
if (EFLAG) evdwl *= factor_lj;
|
|
}
|
|
}
|
|
const double fpair = forcecoul + forcelj;
|
|
|
|
fxtmp += delx*fpair;
|
|
fytmp += dely*fpair;
|
|
fztmp += delz*fpair;
|
|
if (NEWTON_PAIR || j < nlocal) {
|
|
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,
|
|
evdwl,ecoul,fpair,delx,dely,delz,thr);
|
|
}
|
|
}
|
|
f[i].x += fxtmp;
|
|
f[i].y += fytmp;
|
|
f[i].z += fztmp;
|
|
}
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
double PairLJCharmmCoulLongSoftOMP::memory_usage()
|
|
{
|
|
double bytes = memory_usage_thr();
|
|
bytes += PairLJCharmmCoulLongSoft::memory_usage();
|
|
|
|
return bytes;
|
|
}
|