data_MgPb4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.01
_cell_length_b   6.01
_cell_length_c   6.01
_cell_angle_alpha   99.71
_cell_angle_beta   99.71
_cell_angle_gamma   131.5
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgPb4
_chemical_formula_sum   'Mg1 Pb4'
_cell_volume   148.24
_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
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Pb  Pb1  1  0.29  0.78  0.47  1.0
  Pb  Pb2  1  0.58  0.09  0.0  1.0
  Pb  Pb3  1  0.66  0.58  0.0  1.0
  Pb  Pb4  1  0.22  0.29  0.47  1.0

data_MgPb4
_symmetry_space_group_name_H-M   P1
_cell_length_a   4.94
_cell_length_b   6.01
_cell_length_c   6.01
_cell_angle_alpha   80.29
_cell_angle_beta   65.75
_cell_angle_gamma   65.75
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgPb4
_chemical_formula_sum   'Mg1 Pb4'
_cell_volume   148.24
_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
  Mg  Mg0  1  0.0  0.0  0.0  1.0
  Pb  Pb1  1  0.09  0.0  0.49  1.0
  Pb  Pb2  1  0.31  0.47  0.51  1.0
  Pb  Pb3  1  0.58  0.0  0.08  1.0
  Pb  Pb4  1  0.83  0.47  0.92  1.0

Mg Pb Pb Pb Pb
Mg Pb Pb Pb Pb 0 3 - - o 0 2 o o o 0 2 - o o 0 4 o o o 1 4 o o o 1 2 o + + 2 3 o o o 2 3 o - o 3 4 o o - 
MgPb4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 5-coordinate geometry to one Pb(4), two equivalent Pb(2), and two equivalent Pb(3) atoms. The Mg(1)-Pb(4) bond length is 2.60 Å. There is one shorter (2.92 Å) and one longer (3.15 Å) Mg(1)-Pb(2) bond length. There is one shorter (1.93 Å) and one longer (3.08 Å) Mg(1)-Pb(3) bond length. There are four inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 2-coordinate geometry to one Pb(2) and one Pb(4) atom. The Pb(1)-Pb(2) bond length is 2.92 Å. The Pb(1)-Pb(4) bond length is 2.65 Å. In the second Pb site, Pb(2) is bonded in a 2-coordinate geometry to two equivalent Mg(1) and one Pb(1) atom. In the third Pb site, Pb(3) is bonded in a distorted single-bond geometry to two equivalent Mg(1) atoms. In the fourth Pb site, Pb(4) is bonded in a distorted single-bond geometry to one Mg(1) and one Pb(1) atom.