data_NbN2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.89
_cell_length_b   4.89
_cell_length_c   3.13
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NbN2
_chemical_formula_sum   'Nb2 N4'
_cell_volume   74.85
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Nb  Nb4  1  0.0  0.0  0.0  1.0
  Nb  Nb5  1  0.44  0.44  0.57  1.0
  N  N0  1  0.46  0.46  0.0  1.0
  N  N1  1  0.43  0.43  0.0  1.0
  N  N2  1  0.91  0.98  0.57  1.0
  N  N3  1  0.98  0.91  0.57  1.0

data_NbN2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.92
_cell_length_b   6.92
_cell_length_c   3.13
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NbN2
_chemical_formula_sum   'Nb4 N8'
_cell_volume   149.7
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Nb  Nb0  2  0.0  0.0  0.0  1.0
  Nb  Nb1  2  0.44  0.0  0.57  1.0
  N  N2  4  0.44  0.46  0.57  1.0
  N  N3  2  0.43  0.0  0.0  1.0
  N  N4  2  0.46  0.0  0.0  1.0

Nb Nb N N N N