data_Si(AgPb)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.3
_cell_length_b   7.3
_cell_length_c   7.3
_cell_angle_alpha   144.35
_cell_angle_beta   144.35
_cell_angle_gamma   51.31
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si(AgPb)2
_chemical_formula_sum   'Si1 Ag2 Pb2'
_cell_volume   131.36
_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  Si4  1  0.0  0.0  0.0  1.0
  Ag  Ag0  1  0.0  0.0  0.88  1.0
  Ag  Ag1  1  0.0  0.0  0.28  1.0
  Pb  Pb2  1  0.0  0.23  0.29  1.0
  Pb  Pb3  1  0.23  0.0  0.29  1.0

data_Si(AgPb)2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.32
_cell_length_b   6.32
_cell_length_c   7.3
_cell_angle_alpha   90.0
_cell_angle_beta   115.66
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si(AgPb)2
_chemical_formula_sum   'Si2 Ag4 Pb4'
_cell_volume   262.72
_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  0.0  0.0  0.0  1.0
  Ag  Ag1  2  0.28  0.0  0.28  1.0
  Ag  Ag2  2  0.38  0.5  0.88  1.0
  Pb  Pb3  4  0.17  0.12  0.05  1.0

Si Ag Ag Pb Pb
Si Ag Ag Pb Pb 0 1 o o - 0 3 o o o 0 4 o o o 2 3 o o o 2 4 o o o 3 4 o o o 