Files
lammps/src/compute_pair.cpp
2024-01-12 15:25:41 -05:00

141 lines
3.8 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.
------------------------------------------------------------------------- */
#include "compute_pair.h"
#include "error.h"
#include "force.h"
#include "pair.h"
#include "update.h"
#include <cctype>
#include <cstring>
using namespace LAMMPS_NS;
enum { EPAIR, EVDWL, ECOUL };
/* ---------------------------------------------------------------------- */
ComputePair::ComputePair(LAMMPS *lmp, int narg, char **arg) :
Compute(lmp, narg, arg), pstyle(nullptr), pair(nullptr), one(nullptr)
{
if (narg < 4) utils::missing_cmd_args(FLERR, "compute pair", error);
scalar_flag = 1;
extscalar = 1;
peflag = 1;
timeflag = 1;
// copy with suffix so we can later chop it off, if needed
if (lmp->suffix)
pstyle = utils::strdup(fmt::format("{}/{}", arg[3], lmp->suffix));
else
pstyle = utils::strdup(arg[3]);
int iarg = 4;
nsub = 0;
evalue = EPAIR;
if (narg > iarg) {
if (isdigit(arg[iarg][0])) {
nsub = utils::inumeric(FLERR, arg[iarg], false, lmp);
++iarg;
if (nsub <= 0) error->all(FLERR, "Illegal compute pair command");
}
}
if (narg > iarg) {
if (strcmp(arg[iarg], "epair") == 0)
evalue = EPAIR;
else if (strcmp(arg[iarg], "evdwl") == 0)
evalue = EVDWL;
else if (strcmp(arg[iarg], "ecoul") == 0)
evalue = ECOUL;
else
error->all(FLERR, "Unknown compute pair keyword {}", arg[iarg]);
++iarg;
}
// check if pair style with and without suffix exists
pair = force->pair_match(pstyle, 1, nsub);
if (!pair && lmp->suffix) {
pstyle[strlen(pstyle) - strlen(lmp->suffix) - 1] = '\0';
pair = force->pair_match(pstyle, 1, nsub);
}
if (!pair) error->all(FLERR, "Unused pair style {} in compute pair command", pstyle);
npair = pair->nextra;
if (npair) {
vector_flag = 1;
size_vector = npair;
extvector = 1;
one = new double[npair];
vector = new double[npair];
} else
one = vector = nullptr;
}
/* ---------------------------------------------------------------------- */
ComputePair::~ComputePair()
{
delete[] pstyle;
delete[] one;
delete[] vector;
}
/* ---------------------------------------------------------------------- */
void ComputePair::init()
{
// recheck for pair style in case it has been deleted
pair = force->pair_match(pstyle, 1, nsub);
if (!pair) error->all(FLERR, "Unrecognized pair style {} in compute pair command", pstyle);
}
/* ---------------------------------------------------------------------- */
double ComputePair::compute_scalar()
{
invoked_scalar = update->ntimestep;
if (update->eflag_global != invoked_scalar)
error->all(FLERR, "Energy was not tallied on needed timestep");
double eng;
if (evalue == EPAIR)
eng = pair->eng_vdwl + pair->eng_coul;
else if (evalue == EVDWL)
eng = pair->eng_vdwl;
else if (evalue == ECOUL)
eng = pair->eng_coul;
MPI_Allreduce(&eng, &scalar, 1, MPI_DOUBLE, MPI_SUM, world);
return scalar;
}
/* ---------------------------------------------------------------------- */
void ComputePair::compute_vector()
{
invoked_vector = update->ntimestep;
if (update->eflag_global != invoked_vector)
error->all(FLERR, "Energy was not tallied on needed timestep");
for (int i = 0; i < npair; i++) one[i] = pair->pvector[i];
MPI_Allreduce(one, vector, npair, MPI_DOUBLE, MPI_SUM, world);
}