data_[Na2Si2I2O12]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Si  1.9000  1.1000  0.5400
  I  2.6600  1.4000  1.2733
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P-31c]
_cell_length_a [4.9172]
_cell_length_b [4.9172]
_cell_length_c [10.5952]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [163]
_chemical_formula_structural [NaSiIO6]
_chemical_formula_sum '[Na2 Si2 I2 O12]'
_cell_volume [221.8618]
_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  2  0.0000  0.0000  0.0000  1.0
  Si  Si1  2  0.3333  0.6667  0.2500  1.0
  I  I2  2  0.3333  0.6667  0.7500  1.0
  O  O3  12  0.0149  0.3859  0.1513  1.0
]