data_Si2SeCl
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.61
_cell_length_b   3.61
_cell_length_c   7.8
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   119.96
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2SeCl
_chemical_formula_sum   'Si2 Se1 Cl1'
_cell_volume   88.05
_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  Si2  1  0.81  0.0  0.71  1.0
  Si  Si3  1  0.81  0.0  0.08  1.0
  Se  Se1  1  0.0  0.0  0.9  1.0
  Cl  Cl0  1  0.0  0.0  0.0  1.0

data_Si2SeCl
_symmetry_space_group_name_H-M   Cm
_cell_length_a   3.61
_cell_length_b   6.26
_cell_length_c   7.8
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2SeCl
_chemical_formula_sum   'Si4 Se2 Cl2'
_cell_volume   176.1
_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  2  0.31  0.5  0.08  1.0
  Si  Si1  2  0.31  0.5  0.71  1.0
  Se  Se2  2  0.0  0.0  0.9  1.0
  Cl  Cl3  2  0.0  0.0  0.0  1.0

Si Si Se Cl
Si Si Se Cl 0 2 + o o 1 3 + o o 2 3 o o + 