data_MgPb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.4
_cell_length_b   5.4
_cell_length_c   5.4
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgPb
_chemical_formula_sum   'Mg2 Pb2'
_cell_volume   111.57
_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  0.91  0.91  0.91  1.0
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Pb  Pb2  1  0.82  0.82  0.82  1.0
  Pb  Pb3  1  0.73  0.73  0.73  1.0

data_MgPb
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.4
_cell_length_b   5.4
_cell_length_c   13.24
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MgPb
_chemical_formula_sum   'Mg6 Pb6'
_cell_volume   334.72
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Mg  Mg1  3  0.0  0.0  0.09  1.0
  Pb  Pb2  3  0.0  0.0  0.18  1.0
  Pb  Pb3  3  0.0  0.0  0.27  1.0

Mg Mg Pb Pb
PbMg1 crystallizes in the trigonal R3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted linear geometry to one Mg(2) and one Pb(1) atom. The Mg(1)-Mg(2) bond length is 1.18 Å. The Mg(1)-Pb(1) bond length is 1.18 Å. In the second Mg site, Mg(2) is bonded to one Mg(1) and three equivalent Pb(2) atoms to form corner-sharing MgMgPb3 tetrahedra. All Mg(2)-Pb(2) bond lengths are 3.24 Å. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted linear geometry to one Mg(1) and one Pb(2) atom. The Pb(1)-Pb(2) bond length is 1.18 Å. In the second Pb site, Pb(2) is bonded to three equivalent Mg(2) and one Pb(1) atom to form corner-sharing PbMg3Pb tetrahedra.