/* ----------------------------------------------------------------------

   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(cmap,FixCMAP)

#else

#ifndef LMP_FIX_CMAP_H

#define LMP_FIX_CMAP_H

#include "fix.h"

namespace LAMMPS_NS {

class FixCMAP : public Fix {

 public:

  FixCMAP(class LAMMPS *, int, char **);

  ~FixCMAP();

  int setmask();

  void init();

  void setup(int);

  void setup_pre_neighbor();

  void min_setup(int);

  void pre_neighbor();

  void pre_reverse(int, int);

  void post_force(int);

  void post_force_respa(int, int, int);

  void min_post_force(int);

  double compute_scalar();

  void read_data_header(char *);

  void read_data_section(char *, int, char *, tagint);

  bigint read_data_skip_lines(char *);

  void write_data_header(FILE *, int);

  void write_data_section_size(int, int &, int &);

  void write_data_section_pack(int, double **);

  void write_data_section_keyword(int, FILE *);

  void write_data_section(int, FILE *, int, double **, int);

  void write_restart(FILE *);

  void restart(char *);

  int pack_restart(int, double *);

  void unpack_restart(int, int);

  int size_restart(int);

  int maxsize_restart();

  void grow_arrays(int);

  void copy_arrays(int, int, int);

  void set_arrays(int);

  int pack_exchange(int, double *);

  int unpack_exchange(int, double *);

  double memory_usage();

 private:

  int nprocs,me;

  int newton_bond,eflag_caller;

  int ctype,nlevels_respa;

  int ncrosstermtypes,crossterm_per_atom,maxcrossterm;

  int ncrosstermlist;

  bigint ncmap;

  int **crosstermlist;

  int nmax_previous;

  int *num_crossterm;

  int **crossterm_type;

  tagint **crossterm_atom1,**crossterm_atom2,**crossterm_atom3;

  tagint **crossterm_atom4,**crossterm_atom5;

  double E,dEdPhi,dEdPsi;

  double ecmap;

  double fcmap[4],cij[4][4];

  double *g_axis;

  // CMAP grid points obtained from external file

  double ***cmapgrid;

  // partial derivatives and cross-derivatives of the grid data

  double ***d1cmapgrid,***d2cmapgrid,***d12cmapgrid;

  // read map grid data

  void read_grid_map(char *);

  // read in CMAP cross terms from LAMMPS data file

  void read_cmap_data(int, char *);

  // pre-compute the partial and cross-derivatives of map grid points

  void set_map_derivatives(double **, double **, double **, double **);

  // cubic spline interpolation functions for derivatives of map grid points

  void spline(double *, double *, int);

  void spl_interpolate(double, double *, double *, double &, double &);

  // calculate dihedral angles

  double dihedral_angle_atan2(double, double, double, double, double, double,

                              double, double, double, double);

  // calculate bicubic interpolation coefficient matrix c_ij

  void bc_coeff(double *, double *, double *, double *);

  // perform bicubic interpolation at point of interest

  void bc_interpol(double, double, int, int, double *, double *, double *,

                   double *);

};

}

#endif

#endif