144 lines
3.9 KiB
C++
144 lines
3.9 KiB
C++
// clang-format off
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/* ----------------------------------------------------------------------
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LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
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https://www.lammps.org/, Sandia National Laboratories
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Steve Plimpton, sjplimp@sandia.gov
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Copyright (2003) Sandia Corporation. Under the terms of Contract
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DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
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certain rights in this software. This software is distributed under
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the GNU General Public License.
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See the README file in the top-level LAMMPS directory.
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------------------------------------------------------------------------- */
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/* ----------------------------------------------------------------------
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Contributing author: Ilya Valuev (JIHT, Moscow, Russia)
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------------------------------------------------------------------------- */
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#include "fix_nve_awpmd.h"
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#include "pair_awpmd_cut.h"
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#include "atom.h"
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#include "force.h"
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#include "update.h"
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#include "respa.h"
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#include "error.h"
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#include "TCP/wpmd_split.h"
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using namespace LAMMPS_NS;
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using namespace FixConst;
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/* ---------------------------------------------------------------------- */
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FixNVEAwpmd::FixNVEAwpmd(LAMMPS *lmp, int narg, char **arg) :
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Fix(lmp, narg, arg)
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{
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if (!atom->wavepacket_flag)
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error->all(FLERR,"Fix nve/awpmd requires atom style wavepacket");
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time_integrate = 1;
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}
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/* ---------------------------------------------------------------------- */
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int FixNVEAwpmd::setmask()
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{
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int mask = 0;
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mask |= INITIAL_INTEGRATE;
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mask |= FINAL_INTEGRATE;
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mask |= INITIAL_INTEGRATE_RESPA;
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mask |= FINAL_INTEGRATE_RESPA;
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return mask;
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}
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/* ---------------------------------------------------------------------- */
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void FixNVEAwpmd::init()
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{
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dtv = update->dt;
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dtf = 0.5 * update->dt * force->ftm2v;
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if (utils::strmatch(update->integrate_style,"^respa"))
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step_respa = ((Respa *) update->integrate)->step;
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awpmd_pair=(PairAWPMDCut *)force->pair;
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awpmd_pair->wpmd->norm_needed=1;
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}
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/* ----------------------------------------------------------------------
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allow for only per-type mass
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------------------------------------------------------------------------- */
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void FixNVEAwpmd::initial_integrate(int /* vflag */)
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{
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// update v,vr and x,radius of atoms in group
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double **x = atom->x;
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double *eradius = atom->eradius;
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double **v = atom->v;
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double *ervel = atom->ervel;
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double **f = atom->f;
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double *erforce = atom->erforce;
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double **vforce=atom->vforce;
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double *ervelforce=atom->ervelforce;
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double *mass = atom->mass;
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int *type = atom->type;
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int *mask = atom->mask;
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int nlocal = atom->nlocal;
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if (igroup == atom->firstgroup) nlocal = atom->nfirst;
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// x + dt * [v + 0.5 * dt * (f / m)];
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// simple Euler update
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for (int i = 0; i < nlocal; i++) {
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if (mask[i] & groupbit) {
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double dtfm = dtf / mass[type[i]];
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double dtfmr=dtfm;
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for (int j=0;j<3;j++) {
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x[i][j] += dtv*vforce[i][j];
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v[i][j] += dtfm*f[i][j];
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}
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eradius[i]+= dtv*ervelforce[i];
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ervel[i] += dtfmr*erforce[i];
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}
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}
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}
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/* ---------------------------------------------------------------------- */
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void FixNVEAwpmd::final_integrate() {}
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/* ---------------------------------------------------------------------- */
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void FixNVEAwpmd::initial_integrate_respa(int vflag, int ilevel, int /* iloop */)
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{
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dtv = step_respa[ilevel];
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dtf = 0.5 * step_respa[ilevel] * force->ftm2v;
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// innermost level - NVE update of v and x
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// all other levels - NVE update of v
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if (ilevel == 0) initial_integrate(vflag);
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else final_integrate();
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}
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/* ---------------------------------------------------------------------- */
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void FixNVEAwpmd::final_integrate_respa(int ilevel, int /* iloop */)
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{
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dtf = 0.5 * step_respa[ilevel] * force->ftm2v;
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final_integrate();
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}
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/* ---------------------------------------------------------------------- */
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void FixNVEAwpmd::reset_dt()
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{
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dtv = update->dt;
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dtf = 0.5 * update->dt * force->ftm2v;
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}
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