data_Si2SnSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.84
_cell_length_b   5.84
_cell_length_c   5.84
_cell_angle_alpha   139.43
_cell_angle_beta   139.43
_cell_angle_gamma   58.72
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2SnSe
_chemical_formula_sum   'Si2 Sn1 Se1'
_cell_volume   83.51
_cell_formula_units_Z   1
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  Si1  1  0.03  0.0  0.55  1.0
  Si  Si2  1  0.0  0.03  0.55  1.0
  Sn  Sn3  1  0.0  0.0  0.09  1.0
  Se  Se0  1  0.0  0.0  0.0  1.0

data_Si2SnSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.73
_cell_length_b   5.73
_cell_length_c   5.84
_cell_angle_alpha   90.0
_cell_angle_beta   119.36
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2SnSe
_chemical_formula_sum   'Si4 Sn2 Se2'
_cell_volume   167.02
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  0.01  0.01  0.48  1.0
  Sn  Sn1  2  0.0  0.0  0.91  1.0
  Se  Se2  2  0.0  0.0  0.0  1.0

Si Si Sn Se
Si Si Sn Se 0 1 o o o 2 3 o o o 