int pgsize;                      // size of neighbor page

  int oneatom;                     // max # of neighbors for one atom

  int npage;                       // current page in page list

  int *map;

  int *map;                        // 0 (C), 1 (H), or -1 (NULL) for each type

  double cutlj;                    // user-specified LJ cutoff

  double cutljrebosq;              // cut for when to compute

                                   // REBO neighs of ghost atoms