data_[Na8Si4O12]
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
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [4.9938]
_cell_length_b [8.6536]
_cell_length_c [5.5895]
_cell_angle_alpha [90.0000]
_cell_angle_beta [107.8786]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Na2SiO3]
_chemical_formula_sum '[Na8 Si4 O12]'
_cell_volume [229.8826]
_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  4  0.0000  0.3446  0.5000  1
  Na  Na1  2  0.0000  0.0000  0.5000  1
  Na  Na2  2  0.0000  0.5000  0.0000  1
  Si  Si3  4  0.0000  0.1676  0.0000  1
  O  O4  8  0.2412  0.1934  0.8088  1
  O  O5  4  0.1790  0.0000  0.1905  1
]