data_NiN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.86
_cell_length_b   3.86
_cell_length_c   3.86
_cell_angle_alpha   131.37
_cell_angle_beta   131.37
_cell_angle_gamma   71.22
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NiN3
_chemical_formula_sum   'Ni1 N3'
_cell_volume   31.65
_cell_formula_units_Z   1
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
  Ni  Ni3  1  0.0  0.0  0.14  1.0
  N  N0  1  0.59  0.0  0.57  1.0
  N  N1  1  0.0  0.59  0.57  1.0
  N  N2  1  0.0  0.0  0.0  1.0

data_NiN3
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.49
_cell_length_b   4.49
_cell_length_c   3.86
_cell_angle_alpha   90.0
_cell_angle_beta   125.61
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NiN3
_chemical_formula_sum   'Ni2 N6'
_cell_volume   63.29
_cell_formula_units_Z   2
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
  Ni  Ni0  2  0.36  0.5  0.86  1.0
  N  N1  4  0.23  0.21  0.02  1.0
  N  N2  2  0.0  0.0  0.0  1.0

Ni N N N
Ni N N N 0 3 o o o 0 1 - o - 0 2 o - - 1 3 + o + 2 3 o + + 