1 /* -*- c++ -*- ----------------------------------------------------------
2    LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
3    https://www.lammps.org/, Sandia National Laboratories
4    Steve Plimpton, sjplimp@sandia.gov
5 
6    Copyright (2003) Sandia Corporation.  Under the terms of Contract
7    DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
8    certain rights in this software.  This software is distributed under
9    the GNU General Public License.
10 
11    See the README file in the top-level LAMMPS directory.
12 ------------------------------------------------------------------------- */
13 
14 /* ----------------------------------------------------------------------
15    Contributing author: Luca Ferraro (CASPUR)
16    email: luca.ferraro@caspur.it
17 
18    Tersoff Potential
19    References:
20     1) Tersoff, Phys. Rev. B 39, 5566 (1988)
21 ------------------------------------------------------------------------- */
22 
23 #ifdef PAIR_CLASS
24 // clang-format off
25 PairStyle(tersoff/table,PairTersoffTable);
26 // clang-format on
27 #else
28 
29 #ifndef LMP_PAIR_TERSOFF_TABLE_H
30 #define LMP_PAIR_TERSOFF_TABLE_H
31 
32 #include "pair.h"
33 
34 namespace LAMMPS_NS {
35 
36 class PairTersoffTable : public Pair {
37  public:
38   PairTersoffTable(class LAMMPS *);
39   virtual ~PairTersoffTable();
40   virtual void compute(int, int);
41   void settings(int, char **);
42   void coeff(int, char **);
43   void init_style();
44   double init_one(int, int);
45 
46   static constexpr int NPARAMS_PER_LINE = 17;
47 
48  protected:
49   struct Param {
50     double lam1, lam2, lam3;
51     double c, d, h;
52     double gamma, powerm;
53     double powern, beta;
54     double biga, bigb, cutoffR, cutoffS;
55     double cut, cutsq;
56     int ielement, jelement, kelement;
57     int powermint;
58   };
59 
60   double cutmax;    // max cutoff for all elements
61   Param *params;    // parameter set for an I-J-K interaction
62 
63   void allocate();
64 
65   void read_file(char *);
66   void setup_params();
67 
68   // pre-loop coordination functions
69 
70   double **preGtetaFunction, **preGtetaFunctionDerived;
71   double *preCutoffFunction, *preCutoffFunctionDerived;
72   virtual void allocatePreLoops(void);
73   virtual void deallocatePreLoops(void);
74 
75   // grids
76 
77   double minArgumentExponential;
78   double *exponential, ***cutoffFunction, ***cutoffFunctionDerived;
79   double **gtetaFunction, **gtetaFunctionDerived;
80   double **betaZetaPower, **betaZetaPowerDerived;
81 
82   void allocateGrids(void);
83   void deallocateGrids(void);
84 };
85 
86 }    // namespace LAMMPS_NS
87 
88 #endif
89 #endif
90