data_SiSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.92
_cell_length_b   5.92
_cell_length_c   5.92
_cell_angle_alpha   145.11
_cell_angle_beta   132.17
_cell_angle_gamma   60.56
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SiSn
_chemical_formula_sum   'Si2 Sn2'
_cell_volume   87.0
_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  0.77  0.8  0.39  1.0
  Si  Si1  1  0.0  0.6  0.72  1.0
  Sn  Sn2  1  0.0  0.2  0.04  1.0
  Sn  Sn3  1  0.77  0.2  0.07  1.0

data_SiSn
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.55
_cell_length_b   4.8
_cell_length_c   5.92
_cell_angle_alpha   113.92
_cell_angle_beta   107.44
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   SiSn
_chemical_formula_sum   'Si2 Sn2'
_cell_volume   87.0
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  0.1  0.77  0.66  1.0
  Sn  Sn1  2  0.5  0.48  0.37  1.0

Si Si Sn Sn