data_Zn2PbSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.85
_cell_length_b   3.85
_cell_length_c   6.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Zn2PbSe
_chemical_formula_sum   'Zn2 Pb1 Se1'
_cell_volume   97.49
_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  Zn2  1  0.92  0.0  0.66  1.0
  Zn  Zn3  1  0.0  0.92  0.66  1.0
  Pb  Pb0  1  0.92  0.92  0.0  1.0
  Se  Se1  1  0.0  0.0  0.54  1.0

data_Zn2PbSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.44
_cell_length_b   5.44
_cell_length_c   6.58
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Zn2PbSe
_chemical_formula_sum   'Zn4 Pb2 Se2'
_cell_volume   194.98
_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  4  0.46  0.46  0.66  1.0
  Pb  Pb1  2  0.42  0.5  0.0  1.0
  Se  Se2  2  0.0  0.0  0.54  1.0

Zn Zn Pb Se
Zn Zn Pb Se 0 1 + - o 0 2 o - + 0 3 + o o 1 2 - o + 1 3 o + o 