data_Si2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.39
_cell_length_b   8.39
_cell_length_c   2.59
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2Se
_chemical_formula_sum   'Si6 Se3'
_cell_volume   158.13
_cell_formula_units_Z   3
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  Si3  1  0.69  0.0  0.3  1.0
  Si  Si4  1  0.66  0.33  0.3  1.0
  Si  Si5  1  0.85  0.94  0.3  1.0
  Si  Si6  1  0.34  0.33  0.3  1.0
  Si  Si7  1  0.15  0.94  0.3  1.0
  Si  Si8  1  0.7  0.0  0.3  1.0
  Se  Se0  1  0.0  0.0  0.0  1.0
  Se  Se1  1  0.19  0.42  0.3  1.0
  Se  Se2  1  0.0  0.84  0.3  1.0

data_Si2Se
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.59
_cell_length_b   8.39
_cell_length_c   8.39
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2Se
_chemical_formula_sum   'Si6 Se3'
_cell_volume   158.13
_cell_formula_units_Z   3
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  0.3  0.15  0.94  1.0
  Si  Si1  1  0.3  0.34  0.33  1.0
  Si  Si2  1  0.3  0.66  0.33  1.0
  Si  Si3  1  0.3  0.69  0.0  1.0
  Si  Si4  1  0.3  0.7  0.0  1.0
  Si  Si5  1  0.3  0.85  0.94  1.0
  Se  Se6  1  0.0  0.0  0.0  1.0
  Se  Se7  1  0.3  0.0  0.84  1.0
  Se  Se8  1  0.3  0.19  0.42  1.0

Si Si Si Si Si Si Se Se Se