data_Zn2Si2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.1
_cell_length_b   7.1
_cell_length_c   7.1
_cell_angle_alpha   151.12
_cell_angle_beta   151.12
_cell_angle_gamma   41.3
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Zn2Si2Se
_chemical_formula_sum   'Zn2 Si2 Se1'
_cell_volume   83.24
_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
  Zn  Zn3  1  0.0  0.0  0.95  1.0
  Zn  Zn4  1  0.0  0.0  0.34  1.0
  Si  Si1  1  0.0  0.77  0.32  1.0
  Si  Si2  1  0.77  0.0  0.32  1.0
  Se  Se0  1  0.0  0.0  0.0  1.0

data_Zn2Si2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.01
_cell_length_b   5.01
_cell_length_c   7.1
_cell_angle_alpha   90.0
_cell_angle_beta   110.65
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Zn2Si2Se
_chemical_formula_sum   'Zn4 Si4 Se2'
_cell_volume   166.48
_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
  Zn  Zn0  2  0.34  0.0  0.34  1.0
  Zn  Zn1  2  0.45  0.5  0.95  1.0
  Si  Si2  4  0.44  0.12  0.55  1.0
  Se  Se3  2  0.0  0.0  0.0  1.0

Zn Zn Si Si Se