83 lines
2.5 KiB
C++
83 lines
2.5 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: Zheng GONG (ENS de Lyon, z.gong@outlook.com)
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------------------------------------------------------------------------- */
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#include "fix_accelerate_cos.h"
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#include "atom.h"
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#include "domain.h"
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#include "error.h"
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#include "force.h"
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#include "math_const.h"
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#include <cmath>
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using namespace LAMMPS_NS;
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using namespace FixConst;
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/* ---------------------------------------------------------------------- */
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FixAccelerateCos::FixAccelerateCos(LAMMPS *lmp, int narg, char **arg) :
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Fix(lmp, narg, arg) {
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if (narg < 4) error->all(FLERR, "Illegal fix accelerate/cos command");
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acceleration = utils::numeric(FLERR, arg[3],false,lmp);
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if (domain->dimension == 2)
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error->all(FLERR,"Fix accelerate/cos cannot be used with 2d systems");
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}
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/* ---------------------------------------------------------------------- */
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int FixAccelerateCos::setmask() {
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int mask = 0;
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mask |= POST_FORCE;
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return mask;
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}
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/* ---------------------------------------------------------------------- */
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void FixAccelerateCos::setup(int vflag) {
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post_force(vflag);
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}
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/* ---------------------------------------------------------------------- */
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void FixAccelerateCos::post_force(int /* vflag */) {
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double **x = atom->x;
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double **f = atom->f;
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int *type = atom->type;
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double *mass = atom->mass;
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double *rmass = atom->rmass;
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int *mask = atom->mask;
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int nlocal = atom->nlocal;
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double massone, force_x, acc_x;
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double zlo = domain->boxlo[2];
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double zhi = domain->boxhi[2];
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for (int i = 0; i < nlocal; i++)
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if (mask[i] & groupbit) {
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if (rmass) massone = rmass[i];
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else massone = mass[type[i]];
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acc_x = acceleration *
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cos(MathConst::MY_2PI * (x[i][2] - zlo) / (zhi - zlo));
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force_x = acc_x * massone * force->mvv2e;
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f[i][0] += force_x;
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}
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}
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