data_Mg2Bi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.26
_cell_length_b   6.26
_cell_length_c   7.75
_cell_angle_alpha   110.64
_cell_angle_beta   110.64
_cell_angle_gamma   33.38
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mg2Bi
_chemical_formula_sum   'Mg4 Bi2'
_cell_volume   155.53
_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  Mg2  1  0.65  0.0  0.18  1.0
  Mg  Mg3  1  0.66  0.0  0.97  1.0
  Mg  Mg4  1  0.49  0.0  0.23  1.0
  Mg  Mg5  1  0.49  0.0  0.03  1.0
  Bi  Bi0  1  0.23  0.0  0.85  1.0
  Bi  Bi1  1  0.92  0.0  0.36  1.0

data_Mg2Bi
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.6
_cell_length_b   6.26
_cell_length_c   7.75
_cell_angle_alpha   110.64
_cell_angle_beta   90.0
_cell_angle_gamma   106.69
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Mg2Bi
_chemical_formula_sum   'Mg4 Bi2'
_cell_volume   155.53
_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  0.08  0.58  1.0
  Mg  Mg1  2  0.0  0.08  0.37  1.0
  Bi  Bi2  2  0.0  0.34  0.76  1.0

Mg Mg Mg Mg Bi Bi
Mg Mg Mg Mg Bi Bi 0 3 o o o 0 2 o o o 0 5 o o o 1 3 o o + 3 4 o o - 