data_Ba2MgBi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.81
_cell_length_b   4.81
_cell_length_c   7.33
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba2MgBi
_chemical_formula_sum   'Ba2 Mg1 Bi1'
_cell_volume   169.31
_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  0.4  0.4  0.0  1.0
  Ba  Ba1  1  0.0  0.0  0.2  1.0
  Mg  Mg3  1  0.0  0.0  0.58  1.0
  Bi  Bi2  1  0.4  0.4  0.54  1.0

data_Ba2MgBi
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.8
_cell_length_b   6.8
_cell_length_c   7.33
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba2MgBi
_chemical_formula_sum   'Ba4 Mg2 Bi2'
_cell_volume   338.62
_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  0.2  1.0
  Ba  Ba1  2  0.4  0.0  0.0  1.0
  Mg  Mg2  2  0.0  0.0  0.58  1.0
  Bi  Bi3  2  0.4  0.0  0.54  1.0

Ba Ba Mg Bi
Ba2MgBi crystallizes in the monoclinic Cm space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 1-coordinate geometry to two equivalent Bi(1) atoms. There is one shorter (3.41 Å) and one longer (3.91 Å) Ba(1)-Bi(1) bond length. In the second Ba site, Ba(2) is bonded in a distorted single-bond geometry to one Mg(1) and three equivalent Bi(1) atoms. The Ba(2)-Mg(1) bond length is 2.80 Å. There is one shorter (3.69 Å) and two longer (4.25 Å) Ba(2)-Bi(1) bond lengths. Mg(1) is bonded in a 4-coordinate geometry to one Ba(2) and three equivalent Bi(1) atoms. There is one shorter (2.76 Å) and two longer (3.48 Å) Mg(1)-Bi(1) bond lengths. Bi(1) is bonded in a 8-coordinate geometry to two equivalent Ba(1), three equivalent Ba(2), and three equivalent Mg(1) atoms.