Files
lammps/src/fix_langevin.h
2021-05-24 14:18:20 -04:00

161 lines
4.0 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(langevin,FixLangevin);
// clang-format on
#else
#ifndef LMP_FIX_LANGEVIN_H
#define LMP_FIX_LANGEVIN_H
#include "fix.h"
namespace LAMMPS_NS {
class FixLangevin : public Fix {
public:
FixLangevin(class LAMMPS *, int, char **);
virtual ~FixLangevin();
int setmask();
void init();
void setup(int);
virtual void initial_integrate(int);
virtual void post_force(int);
void post_force_respa(int, int, int);
virtual void end_of_step();
void reset_target(double);
void reset_dt();
int modify_param(int, char **);
virtual double compute_scalar();
double memory_usage();
virtual void *extract(const char *, int &);
void grow_arrays(int);
void copy_arrays(int, int, int);
int pack_exchange(int, double *);
int unpack_exchange(int, double *);
protected:
int gjfflag, nvalues, osflag, oflag, tallyflag, zeroflag, tbiasflag;
int flangevin_allocated;
double ascale;
double t_start, t_stop, t_period, t_target;
double *gfactor1, *gfactor2, *ratio;
double energy, energy_onestep;
double tsqrt;
int tstyle, tvar;
double gjfa, gjfsib; //gjf a and gjf sqrt inverse b
char *tstr;
class AtomVecEllipsoid *avec;
int maxatom1, maxatom2;
double **flangevin;
double *tforce;
double **franprev;
double **lv; //half step velocity
char *id_temp;
class Compute *temperature;
int nlevels_respa;
class RanMars *random;
int seed;
template <int Tp_TSTYLEATOM, int Tp_GJF, int Tp_TALLY, int Tp_BIAS, int Tp_RMASS, int Tp_ZERO>
void post_force_templated();
void omega_thermostat();
void angmom_thermostat();
void compute_target();
};
} // 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: Fix langevin period must be > 0.0
The time window for temperature relaxation must be > 0
E: Fix langevin omega requires atom style sphere
Self-explanatory.
E: Fix langevin angmom requires atom style ellipsoid
Self-explanatory.
E: Variable name for fix langevin does not exist
Self-explanatory.
E: Variable for fix langevin is invalid style
It must be an equal-style variable.
E: Fix langevin omega requires extended particles
One of the particles has radius 0.0.
E: Fix langevin angmom requires extended particles
This fix option cannot be used with point particles.
E: Cannot zero Langevin force of 0 atoms
The group has zero atoms, so you cannot request its force
be zeroed.
E: Fix langevin variable returned negative temperature
Self-explanatory.
E: Could not find fix_modify temperature ID
The compute ID for computing temperature does not exist.
E: Fix_modify temperature ID does not compute temperature
The compute ID assigned to the fix must compute temperature.
E: Fix langevin gjf cannot have period equal to dt/2
If the period is equal to dt/2 then division by zero will happen.
E: Fix langevin gjf should come before fix nve
Self-explanatory
E: Fix langevin gjf and respa are not compatible
Self-explanatory
W: Group for fix_modify temp != fix group
The fix_modify command is specifying a temperature computation that
computes a temperature on a different group of atoms than the fix
itself operates on. This is probably not what you want to do.
*/