data_[Si4O8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P6_322]
_cell_length_a [5.1109]
_cell_length_b [5.1109]
_cell_length_c [8.6267]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [182]
_chemical_formula_structural [SiO2]
_chemical_formula_sum '[Si4 O8]'
_cell_volume [195.1474]
_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
[
  Si  Si0  4  0.3333  0.6667  0.5628  1.0
  O  O1  6  0.0000  0.4206  0.5000  1.0
  O  O2  2  0.3333  0.6667  0.7500  1.0
]