data_Ba3Mg2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.59
_cell_length_b   15.59
_cell_length_c   15.59
_cell_angle_alpha   15.74
_cell_angle_beta   15.74
_cell_angle_gamma   15.74
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ba3Mg2
_chemical_formula_sum   'Ba3 Mg2'
_cell_volume   242.76
_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  0.0  1.0
  Ba  Ba1  1  0.0  0.0  0.67  1.0
  Ba  Ba2  1  0.0  0.0  0.5  1.0
  Mg  Mg3  1  0.0  0.0  0.31  1.0
  Mg  Mg4  1  0.0  0.0  0.86  1.0

data_Ba3Mg2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.39
_cell_length_b   4.27
_cell_length_c   15.59
_cell_angle_alpha   90.0
_cell_angle_beta   99.1
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ba3Mg2
_chemical_formula_sum   'Ba6 Mg4'
_cell_volume   485.51
_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  0.5  1.0
  Ba  Ba1  2  0.0  0.0  0.0  1.0
  Ba  Ba2  2  0.0  0.0  0.33  1.0
  Mg  Mg3  2  0.0  0.0  0.14  1.0
  Mg  Mg4  2  0.0  0.0  0.69  1.0

Ba Ba Ba Mg Mg