#ifdef MAIN
#define EXTERN
#else
#define EXTERN extern
#endif


EXTERN int seed;

// Define a vector type
struct vector {
  double  x,y,z;
};

// Define an int vector type
struct ivector {
  int  x,y,z;
};

#define  pi 3.14159265358979
#define  e 1.6021892e-19
#define  u 1.660565e-27
#define  kB 1.380662e-23

// Define some needed unit conversion factors
//
// To get internal units from SI, divide by one of these
// To get SI from internal units, multiply by one of these
//
#define  lunit 1e-10
#define  tunit 1e-15
#define  vunit (lunit/tunit)
#define  aunit (vunit/tunit)
  
// Set array sizes

#define  MAXAT 10000
#define  MAXNEIGHBOURS 100
  
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>