82 lines
1.9 KiB
C++
82 lines
1.9 KiB
C++
/* -*- c++ -*- ----------------------------------------------------------
|
|
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
|
|
https://www.lammps.org/, Sandia National Laboratories
|
|
Steve Plimpton, sjplimp@sandia.gov
|
|
|
|
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.
|
|
------------------------------------------------------------------------- */
|
|
|
|
#ifdef FIX_CLASS
|
|
// clang-format off
|
|
FixStyle(spring,FixSpring);
|
|
// clang-format on
|
|
#else
|
|
|
|
#ifndef LMP_FIX_SPRING_H
|
|
#define LMP_FIX_SPRING_H
|
|
|
|
#include "fix.h"
|
|
|
|
namespace LAMMPS_NS {
|
|
|
|
class FixSpring : public Fix {
|
|
public:
|
|
FixSpring(class LAMMPS *, int, char **);
|
|
~FixSpring();
|
|
int setmask();
|
|
void init();
|
|
void setup(int);
|
|
void min_setup(int);
|
|
void post_force(int);
|
|
void post_force_respa(int, int, int);
|
|
void min_post_force(int);
|
|
double compute_scalar();
|
|
double compute_vector(int);
|
|
|
|
private:
|
|
double xc, yc, zc, r0;
|
|
double k_spring;
|
|
int xflag, yflag, zflag;
|
|
int styleflag;
|
|
char *group2;
|
|
int igroup2, group2bit;
|
|
double masstotal, masstotal2;
|
|
int ilevel_respa;
|
|
double espring, ftotal[4];
|
|
|
|
void spring_tether();
|
|
void spring_couple();
|
|
};
|
|
|
|
} // namespace LAMMPS_NS
|
|
|
|
#endif
|
|
#endif
|
|
|
|
/* ERROR/WARNING messages:
|
|
|
|
E: Illegal ... command
|
|
|
|
Self-explanatory. Check the input script syntax and compare to the
|
|
documentation for the command. You can use -echo screen as a
|
|
command-line option when running LAMMPS to see the offending line.
|
|
|
|
E: R0 < 0 for fix spring command
|
|
|
|
Equilibrium spring length is invalid.
|
|
|
|
E: Fix spring couple group ID does not exist
|
|
|
|
Self-explanatory.
|
|
|
|
E: Two groups cannot be the same in fix spring couple
|
|
|
|
Self-explanatory.
|
|
|
|
*/
|