131 lines
3.6 KiB
C++
131 lines
3.6 KiB
C++
/* ----------------------------------------------------------------------
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LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
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http://lammps.sandia.gov, 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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#include "string.h"
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#include "fix_freeze.h"
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#include "atom.h"
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#include "update.h"
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#include "modify.h"
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#include "comm.h"
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#include "respa.h"
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#include "error.h"
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using namespace LAMMPS_NS;
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/* ---------------------------------------------------------------------- */
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FixFreeze::FixFreeze(LAMMPS *lmp, int narg, char **arg) :
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Fix(lmp, narg, arg)
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{
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if (narg != 3) error->all("Illegal fix freeze command");
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if (!atom->torque_flag)
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error->all("Fix freeze requires atom attribute torque");
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vector_flag = 1;
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size_vector = 3;
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scalar_vector_freq = 1;
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extvector = 1;
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force_flag = 0;
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foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
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}
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/* ---------------------------------------------------------------------- */
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int FixFreeze::setmask()
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{
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int mask = 0;
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mask |= POST_FORCE;
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mask |= POST_FORCE_RESPA;
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return mask;
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}
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/* ---------------------------------------------------------------------- */
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void FixFreeze::init()
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{
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// error if more than one freeze fix
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// because accessed by pair style granular and fix gran/diag
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int count = 0;
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for (int i = 0; i < modify->nfix; i++)
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if (strcmp(modify->fix[i]->style,"freeze") == 0) count++;
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if (count > 1) error->all("More than one fix freeze");
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}
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/* ---------------------------------------------------------------------- */
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void FixFreeze::setup(int vflag)
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{
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if (strcmp(update->integrate_style,"verlet") == 0)
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post_force(vflag);
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else {
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int nlevels_respa = ((Respa *) update->integrate)->nlevels;
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for (int ilevel = 0; ilevel < nlevels_respa; ilevel++) {
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((Respa *) update->integrate)->copy_flevel_f(ilevel);
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post_force_respa(vflag,ilevel,0);
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((Respa *) update->integrate)->copy_f_flevel(ilevel);
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}
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}
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}
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/* ---------------------------------------------------------------------- */
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void FixFreeze::post_force(int vflag)
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{
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double **f = atom->f;
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double **torque = atom->torque;
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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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foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
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force_flag = 0;
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for (int i = 0; i < nlocal; i++)
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if (mask[i] & groupbit) {
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foriginal[0] += f[i][0];
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foriginal[1] += f[i][1];
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foriginal[2] += f[i][2];
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f[i][0] = 0.0;
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f[i][1] = 0.0;
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f[i][2] = 0.0;
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torque[i][0] = 0.0;
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torque[i][1] = 0.0;
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torque[i][2] = 0.0;
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}
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}
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/* ---------------------------------------------------------------------- */
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void FixFreeze::post_force_respa(int vflag, int ilevel, int iloop)
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{
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post_force(vflag);
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}
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/* ----------------------------------------------------------------------
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return components of total force on fix group before force was changed
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------------------------------------------------------------------------- */
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double FixFreeze::compute_vector(int n)
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{
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// only sum across procs one time
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if (force_flag == 0) {
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MPI_Allreduce(foriginal,foriginal_all,3,MPI_DOUBLE,MPI_SUM,world);
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force_flag = 1;
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}
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return foriginal_all[n];
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}
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