data_YMg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   8.08
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YMg
_chemical_formula_sum   'Y2 Mg2'
_cell_volume   172.46
_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
  Y  Y0  1  0.48  0.43  0.07  1.0
  Y  Y1  1  0.0  0.87  0.03  1.0
  Mg  Mg2  1  0.48  0.43  0.04  1.0
  Mg  Mg3  1  0.0  0.87  0.07  1.0

data_YMg
_symmetry_space_group_name_H-M   P-1
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   8.08
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   YMg
_chemical_formula_sum   'Y2 Mg2'
_cell_volume   172.46
_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
  Y  Y0  2  0.24  0.28  0.02  1.0
  Mg  Mg1  2  0.24  0.28  0.99  1.0

Y Y Mg Mg
Y Y Mg Mg 0 2 o o o 1 3 o o o 