data_Zn2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.98
_cell_length_b   5.98
_cell_length_c   6.71
_cell_angle_alpha   121.57
_cell_angle_beta   121.57
_cell_angle_gamma   35.27
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Zn2Se
_chemical_formula_sum   'Zn4 Se2'
_cell_volume   115.82
_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
  Zn  Zn2  1  0.98  0.0  0.64  1.0
  Zn  Zn3  1  0.72  0.0  0.3  1.0
  Zn  Zn4  1  0.0  0.0  0.31  1.0
  Zn  Zn5  1  0.74  0.0  0.96  1.0
  Se  Se0  1  0.51  0.0  0.97  1.0
  Se  Se1  1  0.21  0.0  0.63  1.0

data_Zn2Se
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.63
_cell_length_b   5.98
_cell_length_c   6.23
_cell_angle_alpha   66.6
_cell_angle_beta   73.07
_cell_angle_gamma   72.36
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Zn2Se
_chemical_formula_sum   'Zn4 Se2'
_cell_volume   115.82
_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
  Zn  Zn0  2  0.0  0.28  0.34  1.0
  Zn  Zn1  2  0.0  0.36  0.99  1.0
  Se  Se2  2  0.0  0.48  0.67  1.0

Zn Zn Zn Zn Se Se