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/* -*- c++ -*- ----------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, 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
FixStyle(spring,FixSpring)
#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();
};
}
#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.
*/