data_SiSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.49
_cell_length_b   5.49
_cell_length_c   5.49
_cell_angle_alpha   112.54
_cell_angle_beta   112.54
_cell_angle_gamma   103.49
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiSe2
_chemical_formula_sum   'Si2 Se4'
_cell_volume   126.46
_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  Si4  1  0.0  0.0  0.1  1.0
  Si  Si5  1  0.0  0.0  0.7  1.0
  Se  Se0  1  0.87  0.18  0.0  1.0
  Se  Se1  1  0.18  0.87  0.4  1.0
  Se  Se2  1  0.92  0.87  0.0  1.0
  Se  Se3  1  0.13  0.18  0.4  1.0

data_SiSe2
_symmetry_space_group_name_H-M   P1
_cell_length_a   5.49
_cell_length_b   5.49
_cell_length_c   5.49
_cell_angle_alpha   103.49
_cell_angle_beta   112.54
_cell_angle_gamma   112.54
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiSe2
_chemical_formula_sum   'Si2 Se4'
_cell_volume   126.46
_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  1  0.1  0.1  0.1  1.0
  Si  Si1  1  0.7  0.7  0.7  1.0
  Se  Se2  1  -0.0  0.13  0.82  1.0
  Se  Se3  1  -0.0  0.08  0.13  1.0
  Se  Se4  1  0.4  0.22  0.53  1.0
  Se  Se5  1  0.4  0.27  0.22  1.0

Si Si Se Se Se Se