data_[Na8Nb4Cl28]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Nb  1.6000  1.4500  0.8200
  Cl  3.1600  1.0000  0.7800
]
_symmetry_space_group_name_H-M [C2/c]
_cell_length_a [18.1229]
_cell_length_b [8.0846]
_cell_length_c [12.4466]
_cell_angle_alpha [90.0000]
_cell_angle_beta [132.0350]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [15]
_chemical_formula_structural [Na2NbCl7]
_chemical_formula_sum '[Na8 Nb4 Cl28]'
_cell_volume [1354.4695]
_cell_formula_units_Z [4]
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  8  0.0271  0.7498  0.0718  1
  Nb  Nb1  4  0.0000  0.1762  0.2500  1
  Cl  Cl2  8  0.0458  0.5727  0.6838  1
  Cl  Cl3  8  0.1009  0.0775  0.1897  1
  Cl  Cl4  8  0.1487  0.1701  0.4953  1
  Cl  Cl5  4  0.0000  0.1400  0.7500  1
]