data_[Si4Se4O2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  Se  2.5500  1.1500  1.0133
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P4/mbm]
_cell_length_a [6.7012]
_cell_length_b [6.7012]
_cell_length_c [3.6365]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [127]
_chemical_formula_structural [Si2Se2O]
_chemical_formula_sum '[Si4 Se4 O2]'
_cell_volume [163.3015]
_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
[
  Si  Si0  4  0.1921  0.3079  0.0000  1
  Se  Se1  4  0.1482  0.6482  0.5000  1
  O  O2  2  0.0000  0.0000  0.0000  1
]