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 [Pna2_1]
_cell_length_a [5.0837]
_cell_length_b [7.0418]
_cell_length_c [5.0665]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [33]
_chemical_formula_structural [SiO2]
_chemical_formula_sum '[Si4 O8]'
_cell_volume [181.3710]
_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  0.0454  0.6248  0.9996  1.0
  O  O1  4  0.0158  0.5521  0.3029  1.0
  O  O2  4  0.1561  0.1992  0.4475  1.0
]