data_CuPb2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.45
_cell_length_b   5.45
_cell_length_c   5.45
_cell_angle_alpha   132.57
_cell_angle_beta   118.66
_cell_angle_gamma   81.02
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuPb2Se
_chemical_formula_sum   'Cu1 Pb2 Se1'
_cell_volume   101.13
_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
  Cu  Cu0  1  0.0  0.0  0.0  1.0
  Pb  Pb1  1  0.19  0.0  0.88  1.0
  Pb  Pb2  1  0.0  0.78  0.27  1.0
  Se  Se3  1  0.0  0.0  0.15  1.0

data_CuPb2Se
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.39
_cell_length_b   5.45
_cell_length_c   5.45
_cell_angle_alpha   61.34
_cell_angle_beta   66.29
_cell_angle_gamma   66.29
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CuPb2Se
_chemical_formula_sum   'Cu1 Pb2 Se1'
_cell_volume   101.13
_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
  Cu  Cu0  1  0.0  0.0  0.0  1.0
  Pb  Pb1  1  0.0  0.81  0.88  1.0
  Pb  Pb2  1  0.78  0.0  0.48  1.0
  Se  Se3  1  0.0  0.0  0.15  1.0

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