data_[Na2Ni2N2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ni  1.9100  1.3500  0.7400
  N  3.0400  0.6500  0.6300
]
_symmetry_space_group_name_H-M [Pm]
_cell_length_a [3.3706]
_cell_length_b [4.3070]
_cell_length_c [5.2781]
_cell_angle_alpha [90.0000]
_cell_angle_beta [95.8599]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [6]
_chemical_formula_structural [NaNiN]
_chemical_formula_sum '[Na2 Ni2 N2]'
_cell_volume [76.2220]
_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
[
  Na  Na0  1  0.3232  0.0000  0.6868  1
  Na  Na1  1  0.9275  0.0000  0.1617  1
  Ni  Ni2  1  0.4079  0.5000  0.0638  1
  Ni  Ni3  1  0.7688  0.5000  0.5021  1
  N  N4  1  0.2558  0.5000  0.3843  1
  N  N5  1  0.8351  0.5000  0.8552  1
]