Files
lammps/src/LEPTON/pair_lepton_sphere.cpp
2023-03-28 21:03:20 -04:00

232 lines
7.6 KiB
C++

/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
https://www.lammps.org/, Sandia National Laboratories
LAMMPS development team: developers@lammps.org
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. 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 "pair_lepton_sphere.h"
#include "atom.h"
#include "comm.h"
#include "error.h"
#include "force.h"
#include "memory.h"
#include "neigh_list.h"
#include "neighbor.h"
#include "update.h"
#include "Lepton.h"
#include "lepton_utils.h"
#include <cmath>
using namespace LAMMPS_NS;
/* ---------------------------------------------------------------------- */
void PairLeptonSphere::compute(int eflag, int vflag)
{
ev_init(eflag, vflag);
if (evflag) {
if (eflag) {
if (force->newton_pair)
eval<1, 1, 1>();
else
eval<1, 1, 0>();
} else {
if (force->newton_pair)
eval<1, 0, 1>();
else
eval<1, 0, 0>();
}
} else {
if (force->newton_pair)
eval<0, 0, 1>();
else
eval<0, 0, 0>();
}
if (vflag_fdotr) virial_fdotr_compute();
}
/* ---------------------------------------------------------------------- */
template <int EVFLAG, int EFLAG, int NEWTON_PAIR> void PairLeptonSphere::eval()
{
const double *const *const x = atom->x;
double *const *const f = atom->f;
const double *const radius = atom->radius;
const int *const type = atom->type;
const int nlocal = atom->nlocal;
const double *const special_lj = force->special_lj;
const int inum = list->inum;
const int *const ilist = list->ilist;
const int *const numneigh = list->numneigh;
const int *const *const firstneigh = list->firstneigh;
double fxtmp, fytmp, fztmp;
std::vector<Lepton::CompiledExpression> pairforce;
std::vector<Lepton::CompiledExpression> pairpot;
std::vector<std::pair<bool, bool>> have_rad;
try {
for (const auto &expr : expressions) {
auto parsed = Lepton::Parser::parse(LeptonUtils::substitute(expr, lmp), functions);
pairforce.emplace_back(parsed.differentiate("r").createCompiledExpression());
if (EFLAG) pairpot.emplace_back(parsed.createCompiledExpression());
pairforce.back().getVariableReference("r");
have_rad.emplace_back(true, true);
// check if there are references to charges
try {
pairforce.back().getVariableReference("radi");
} catch (std::exception &) {
have_rad.back().first = false;
}
try {
pairforce.back().getVariableReference("radj");
} catch (std::exception &) {
have_rad.back().second = false;
}
}
} catch (std::exception &e) {
error->all(FLERR, e.what());
}
// loop over neighbors of my atoms
for (int ii = 0; ii < inum; ii++) {
const int i = ilist[ii];
const double xtmp = x[i][0];
const double ytmp = x[i][1];
const double ztmp = x[i][2];
const int itype = type[i];
const int *jlist = firstneigh[i];
const int jnum = numneigh[i];
fxtmp = fytmp = fztmp = 0.0;
for (int jj = 0; jj < jnum; jj++) {
int j = jlist[jj];
const double factor_lj = special_lj[sbmask(j)];
j &= NEIGHMASK;
const int jtype = type[j];
const double delx = xtmp - x[j][0];
const double dely = ytmp - x[j][1];
const double delz = ztmp - x[j][2];
const double rsq = delx * delx + dely * dely + delz * delz;
if (rsq < cutsq[itype][jtype]) {
const double r = sqrt(rsq);
const int idx = type2expression[itype][jtype];
pairforce[idx].getVariableReference("r") = r;
if (have_rad[idx].first) pairforce[idx].getVariableReference("radi") = radius[i];
if (have_rad[idx].second) pairforce[idx].getVariableReference("radj") = radius[j];
const double fpair = -pairforce[idx].evaluate() / r * factor_lj;
fxtmp += delx * fpair;
fytmp += dely * fpair;
fztmp += delz * fpair;
if (NEWTON_PAIR || (j < nlocal)) {
f[j][0] -= delx * fpair;
f[j][1] -= dely * fpair;
f[j][2] -= delz * fpair;
}
double evdwl = 0.0;
if (EFLAG) {
pairpot[idx].getVariableReference("r") = r;
if (have_rad[idx].first) pairpot[idx].getVariableReference("radi") = radius[i];
if (have_rad[idx].second) pairpot[idx].getVariableReference("radj") = radius[j];
evdwl = pairpot[idx].evaluate();
evdwl *= factor_lj;
}
if (EVFLAG) ev_tally(i, j, nlocal, NEWTON_PAIR, evdwl, 0.0, fpair, delx, dely, delz);
}
}
f[i][0] += fxtmp;
f[i][1] += fytmp;
f[i][2] += fztmp;
}
}
/* ----------------------------------------------------------------------
global settings
------------------------------------------------------------------------- */
void PairLeptonSphere::settings(int narg, char **arg)
{
if (narg != 1)
error->all(FLERR, "Incorrect number of arguments for pair_style lepton/sphere command");
cut_global = utils::numeric(FLERR, arg[0], false, lmp);
}
/* ---------------------------------------------------------------------- */
void PairLeptonSphere::init_style()
{
if (!atom->radius_flag)
error->all(FLERR, "Pair style lepton/sphere requires atom attribute radius");
if (offset_flag) error->all(FLERR, "Pair style lepton/sphere does not suport pair_modify shift");
neighbor->add_request(this);
}
/* ----------------------------------------------------------------------
proc 0 writes to restart file
------------------------------------------------------------------------- */
void PairLeptonSphere::write_restart_settings(FILE *fp)
{
fwrite(&cut_global, sizeof(double), 1, fp);
}
/* ----------------------------------------------------------------------
proc 0 reads from restart file, bcasts
------------------------------------------------------------------------- */
void PairLeptonSphere::read_restart_settings(FILE *fp)
{
if (comm->me == 0) { utils::sfread(FLERR, &cut_global, sizeof(double), 1, fp, nullptr, error); }
MPI_Bcast(&cut_global, 1, MPI_DOUBLE, 0, world);
}
/* ---------------------------------------------------------------------- */
double PairLeptonSphere::single(int i, int j, int itype, int jtype, double rsq,
double /* factor_coul */, double factor_lj, double &fforce)
{
auto expr = expressions[type2expression[itype][jtype]];
auto parsed = Lepton::Parser::parse(LeptonUtils::substitute(expr, lmp), functions);
auto pairpot = parsed.createCompiledExpression();
auto pairforce = parsed.differentiate("r").createCompiledExpression();
const double r = sqrt(rsq);
pairpot.getVariableReference("r") = r;
pairforce.getVariableReference("r") = r;
try {
pairpot.getVariableReference("radi") = atom->radius[i];
pairforce.getVariableReference("radi") = atom->radius[i];
} catch (std::exception &) {
/* ignore */
}
try {
pairpot.getVariableReference("radj") = atom->radius[j];
pairforce.getVariableReference("radj") = atom->radius[j];
} catch (std::exception &) {
/* ignore */
}
fforce = -pairforce.evaluate() / r * factor_lj;
return pairpot.evaluate() * factor_lj;
}