data_[Na16Sn2As4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Sn  1.9600  1.4500  0.8300
  As  2.1800  1.1500  0.6600
]
_symmetry_space_group_name_H-M [Immm]
_cell_length_a [5.0032]
_cell_length_b [8.5361]
_cell_length_c [13.3960]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [71]
_chemical_formula_structural [Na8SnAs2]
_chemical_formula_sum '[Na16 Sn2 As4]'
_cell_volume [572.1102]
_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  8  0.0000  0.2084  0.3370  1
  Na  Na1  4  0.0000  0.0000  0.1510  1
  Na  Na2  4  0.0000  0.3137  0.0000  1
  Sn  Sn3  2  0.0000  0.5000  0.5000  1
  As  As4  4  0.0000  0.5000  0.2028  1
]