data_[Na2Ca2N2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ca  1.0000  1.8000  1.1400
  N  3.0400  0.6500  0.6300
]
_symmetry_space_group_name_H-M [Pm]
_cell_length_a [6.7506]
_cell_length_b [3.5753]
_cell_length_c [18.4404]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [6]
_chemical_formula_structural [NaCaN]
_chemical_formula_sum '[Na2 Ca2 N2]'
_cell_volume [445.0708]
_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  0.3335  0.5000  0.5903  1
  Na  Na1  1  0.8159  0.0000  0.5716  1
  Ca  Ca2  1  0.1265  0.0000  0.4370  1
  Ca  Ca3  1  0.6441  0.5000  0.4038  1
  N  N4  1  0.0514  0.5000  0.5216  1
  N  N5  1  0.9010  0.5000  0.4757  1
]