/********************************************/
/* Program To Fit Finnis-Sinclair Potential */
/*                                          */
/*           V1.0  May 13 2000  Ju Li (MIT) */
/********************************************/

#include <signal.h>
#include <Atoms.h>
#include <Min.h>

/* atom */
#define MAX_TYPE            2
#define Zr_ATOM             0
#define C_ATOM              1
#define MAX_ATOM            8
/* interaction */
#define MAX_FIRST           32
#define MAX_IMAGE           256
/* structure */
#define NaCl                0
#define ZnS                 1
#define CsCl                2
#define ZrVAC               3
#define CVAC                4
#define PureZr              5
#define PureC               6
#define ZrC_CDIS            7
#define ZrC_ZrDIS           8
#define DIS_DEL            (DELTA*100)
#define ZrC_TEST            9
#define TEST_DEL           (SMALL/100)
#define MAX_STRUCTURE       10
/* target */
#define LATTICE_CONSTANT    4.695
#define MAX_XTAL_STRUCTURE  3
#define XTAL_EQ_A           0
#define XTAL_EQ_POTE        1
#define MAX_XTAL_PROPERTY   2
/* parameter */
#define MAX_CATEGORY        8
#define MAX_OP              16
/* info */
#define REP_FILENAME        "rep"
#define SIG_SUCCESS         SIGUSR1

typedef struct
{
    char *name;      /* structure name */
    double H[3][3];  /* Bravais lattice measured in a */
    double volume;   /* cell volume in a^3 */
    double HI[3][3]; /* matrix inverse of H[3][3] */
    int n;           /* number of atoms in this unit cell */
    int *t;          /* atom type specified in Z[] */
    double mass;     /* mass of the unit cell in g */
    double *s;       /* x = s . H */
    double *ds;      /* neighbor atom delta s */
    double a;        /* lattice constant in A */
    double *dx;      /* neighbor atom delta x */
    double *X;       /* embedding function of each atom */
    double pote;     /* potential energy [eV] / unit cell */
    bool calculate_force;  /* carry out force calculation */
    double *f;       /* force in x,y,z directions */
} Structure;

/* main.c: */

void construct_neighbor_list (Structure *S);
double potential_energy (Structure *S, double param[MAX_OP]);
double fe (double guess[MAX_OP]);
void wrap_up (int sig);

/* targets.c: */

/* Equilibrium lattice constant [A], energy per unit cell [eV] */
extern const int Z[MAX_TYPE];
extern const double xtal_target[MAX_XTAL_STRUCTURE][MAX_XTAL_PROPERTY];
extern const double c11_target, c12_target, c44_target; /* in GPa */
#define bulk_modulus_target ((c11_target+2*c12_target)/3)
extern const double schottky_energy_target;
extern const double NaCl_cohesive_energy_target; /* eV/pair */
extern const double PureZr_atomic_volume_target; /* in A^3 */
extern const double PureZr_bulk_modulus_target; /* in GPa */
extern const double PureZr_cohesive_energy_target; /* eV/atom */
extern const double PureC_atomic_volume_target; /* in A^3 */
extern const double PureC_bulk_modulus_target; /* in GPa */
extern const double PureC_cohesive_energy_target; /* eV/atom */
extern const double ZrC_CDIS_fx_target [8];
extern const double ZrC_ZrDIS_fx_target [8];
extern const double heat_of_formation_target;

extern Structure my[MAX_STRUCTURE], *this_structure;
extern int n_category, category_ops[MAX_CATEGORY];
extern TermString category_name[MAX_CATEGORY];
extern double bound[2][MAX_OP], param[MAX_OP];
extern double lattice_constant_range[MAX_STRUCTURE][2];
extern double xtal_weight[MAX_STRUCTURE][MAX_XTAL_PROPERTY], exponent;
extern double bulk_modulus_weight, c11_weight, c12_weight, c44_weight;
extern double schottky_energy_weight;
extern double bulk_modulus, c11, c12, c44, schottky_energy;
extern double PureZr_atomic_volume_weight, PureZr_bulk_modulus_weight;
extern double PureZr_cohesive_energy_weight;
extern double PureC_atomic_volume_weight, PureC_bulk_modulus_weight;
extern double PureC_cohesive_energy_weight;
extern double heat_of_formation_weight, ZrC_CDIS_fx_weight[8],
    ZrC_ZrDIS_fx_weight[8];
extern int print_freq, maxkb, just_print_it, kb;

/* elastic_constants.c: */
double Bulk_Modulus (Structure *S);
double C11_C12 (Structure *S);
double C44_0 (Structure *S);

/* info.c: */
void print_param (FILE *out);
void print_property (FILE *out);
void plot_cohesive_energy_curves (char filename[]);
void write_config (Structure *S, double x0[3], double H0[3][3],
                   double magnification, char filename[]);