data_[Si6Se6]
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
]
_symmetry_space_group_name_H-M [P-3m1]
_cell_length_a [3.6184]
_cell_length_b [3.6184]
_cell_length_c [24.7418]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [164]
_chemical_formula_structural [SiSe]
_chemical_formula_sum '[Si6 Se6]'
_cell_volume [280.5367]
_cell_formula_units_Z [6]
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  2  0.0000  0.0000  0.2991  1
  Si  Si1  2  0.3333  0.6667  0.6351  1
  Si  Si2  2  0.3333  0.6667  0.9671  1
  Se  Se3  2  0.0000  0.0000  0.0867  1
  Se  Se4  2  0.3333  0.6667  0.2453  1
  Se  Se5  2  0.3333  0.6667  0.4187  1
]