data_SbPb3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.48
_cell_length_b   5.02
_cell_length_c   7.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SbPb3
_chemical_formula_sum   'Sb1 Pb3'
_cell_volume   122.37
_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
  Sb  Sb3  1  0.0  0.0  0.0  1.0
  Pb  Pb0  1  0.74  0.51  0.31  1.0
  Pb  Pb1  1  0.0  0.0  0.5  1.0
  Pb  Pb2  1  0.74  0.51  0.69  1.0

data_SbPb3
_symmetry_space_group_name_H-M   Pmm2
_cell_length_a   5.02
_cell_length_b   7.0
_cell_length_c   3.48
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   25
_chemical_formula_structural   SbPb3
_chemical_formula_sum   'Sb1 Pb3'
_cell_volume   122.37
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, z'
  3  '-x, y, z'
  4  '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
  Sb  Sb0  1  0.0  0.0  0.0  1.0
  Pb  Pb1  2  0.5  0.31  0.74  1.0
  Pb  Pb2  1  0.0  0.5  0.0  1.0

Sb Pb Pb Pb
Sb Pb Pb Pb 0 3 - - - 0 3 - o - 0 1 - - o 0 1 - o o 0 0 + o o 0 2 o o - 0 2 o o o 1 1 + o o 1 2 + o o 1 2 + + o 1 3 o o o 2 3 - - o 2 3 - o o 2 2 + o o 3 3 + o o 
Pb3Sb is Magnesium tetraboride-like structured and crystallizes in the monoclinic Pm space group. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 7-coordinate geometry to two equivalent Pb(2), three equivalent Pb(1), and two equivalent Sb(1) atoms. There is one shorter (2.95 Å) and one longer (3.02 Å) Pb(1)-Pb(2) bond length. There is one shorter (2.68 Å) and two longer (3.48 Å) Pb(1)-Pb(1) bond lengths. There is one shorter (3.40 Å) and one longer (3.46 Å) Pb(1)-Sb(1) bond length. In the second Pb site, Pb(2) is bonded to two equivalent Pb(2), four equivalent Pb(1), and two equivalent Sb(1) atoms to form a mixture of distorted corner and edge-sharing PbSb2Pb6 hexagonal bipyramids. Both Pb(2)-Pb(2) bond lengths are 3.48 Å. Both Pb(2)-Sb(1) bond lengths are 3.50 Å. Sb(1) is bonded in a 8-coordinate geometry to two equivalent Pb(2), four equivalent Pb(1), and two equivalent Sb(1) atoms. Both Sb(1)-Sb(1) bond lengths are 3.48 Å.