data_[Si8O16]
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 [Pccn]
_cell_length_a [4.6807]
_cell_length_b [8.1225]
_cell_length_c [8.3922]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [56]
_chemical_formula_structural [SiO2]
_chemical_formula_sum '[Si8 O16]'
_cell_volume [319.0623]
_cell_formula_units_Z [8]
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  8  0.1525  0.0625  0.6593  1
  O  O1  8  0.0717  0.5540  0.6925  1
  O  O2  4  0.0000  0.0000  0.5000  1
  O  O3  4  0.2500  0.2500  0.1365  1
]