data_Mg2Pb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.21
_cell_length_b   6.21
_cell_length_c   7.83
_cell_angle_alpha   108.81
_cell_angle_beta   108.81
_cell_angle_gamma   32.26
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Pb
_chemical_formula_sum   'Mg4 Pb2'
_cell_volume   151.84
_cell_formula_units_Z   2
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  0.65  0.0  0.2  1.0
  Mg  Mg1  1  0.51  0.0  0.23  1.0
  Mg  Mg2  1  0.8  0.0  0.14  1.0
  Mg  Mg3  1  0.66  0.0  0.17  1.0
  Pb  Pb4  1  0.4  0.0  0.83  1.0
  Pb  Pb5  1  0.91  0.0  0.54  1.0

data_Mg2Pb
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.45
_cell_length_b   6.21
_cell_length_c   7.83
_cell_angle_alpha   108.81
_cell_angle_beta   90.0
_cell_angle_gamma   106.13
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Mg2Pb
_chemical_formula_sum   'Mg4 Pb2'
_cell_volume   151.84
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  2  0.0  0.01  0.48  1.0
  Mg  Mg1  2  0.0  0.14  0.45  1.0
  Pb  Pb2  2  0.0  0.25  0.86  1.0

Mg Mg Mg Mg Pb Pb
Mg Mg Mg Mg Pb Pb 0 3 o o o 0 1 o o o 0 4 o o - 0 5 o o o 1 4 o o - 1 5 o o o 2 3 o o o 2 4 o o - 2 5 o o o 3 4 o o - 3 5 o o o 4 5 - o o 
Mg2Pb crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one Mg2Pb cluster. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted single-bond geometry to one Mg(1), one Mg(2), and one Pb(1) atom. The Mg(1)-Mg(1) bond length is 0.31 Å. The Mg(1)-Mg(2) bond length is 0.95 Å. The Mg(1)-Pb(1) bond length is 2.61 Å. In the second Mg site, Mg(2) is bonded in a single-bond geometry to one Mg(1) atom. Pb(1) is bonded in a distorted single-bond geometry to one Mg(1) atom.