data_Al2Si2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.23
_cell_length_b   7.23
_cell_length_c   7.23
_cell_angle_alpha   151.36
_cell_angle_beta   151.36
_cell_angle_gamma   40.95
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Al2Si2Se
_chemical_formula_sum   'Al2 Si2 Se1'
_cell_volume   86.68
_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
  Al  Al0  1  0.0  0.0  0.17  1.0
  Al  Al1  1  0.0  0.0  0.38  1.0
  Si  Si3  1  0.0  0.79  0.39  1.0
  Si  Si4  1  0.79  0.0  0.39  1.0
  Se  Se2  1  0.0  0.0  0.0  1.0

data_Al2Si2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.06
_cell_length_b   5.06
_cell_length_c   7.23
_cell_angle_alpha   90.0
_cell_angle_beta   110.48
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Al2Si2Se
_chemical_formula_sum   'Al4 Si4 Se2'
_cell_volume   173.37
_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
  Al  Al0  2  0.17  0.0  0.17  1.0
  Al  Al1  2  0.38  0.0  0.38  1.0
  Si  Si2  4  0.49  0.11  0.6  1.0
  Se  Se3  2  0.0  0.0  0.0  1.0

Al Al Si Si Se