data_Ba2MgPb2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.85
_cell_length_b   10.85
_cell_length_c   10.85
_cell_angle_alpha   155.77
_cell_angle_beta   155.77
_cell_angle_gamma   34.53
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2MgPb2
_chemical_formula_sum   'Ba2 Mg1 Pb2'
_cell_volume   215.0
_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
  Ba  Ba0  1  0.0  0.0  0.54  1.0
  Ba  Ba1  1  0.0  0.0  0.19  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Pb  Pb3  1  0.0  0.28  0.18  1.0
  Pb  Pb4  1  0.28  0.0  0.18  1.0

data_Ba2MgPb2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.44
_cell_length_b   6.44
_cell_length_c   10.85
_cell_angle_alpha   90.0
_cell_angle_beta   107.26
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2MgPb2
_chemical_formula_sum   'Ba4 Mg2 Pb4'
_cell_volume   430.0
_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
  Ba  Ba0  2  0.0  0.0  0.46  1.0
  Ba  Ba1  2  0.0  0.0  0.81  1.0
  Mg  Mg2  2  0.0  0.0  0.0  1.0
  Pb  Pb3  4  0.14  0.86  0.1  1.0

Ba Ba Mg Pb Pb
Ba2MgPb2 crystallizes in the monoclinic Cm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to one Ba(2), four equivalent Ba(1), and two equivalent Pb(1) atoms. The Ba(1)-Ba(2) bond length is 3.82 Å. All Ba(1)-Ba(1) bond lengths are 4.55 Å. Both Ba(1)-Pb(1) bond lengths are 4.40 Å. In the second Ba site, Ba(2) is bonded in a single-bond geometry to one Ba(1) and one Mg(1) atom. The Ba(2)-Mg(1) bond length is 2.04 Å. Mg(1) is bonded in a 3-coordinate geometry to one Ba(2) and two equivalent Pb(1) atoms. Both Mg(1)-Pb(1) bond lengths are 1.46 Å. Pb(1) is bonded in a single-bond geometry to one Ba(1) and one Mg(1) atom.