data_CeMg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.82
_cell_length_b   5.48
_cell_length_c   5.69
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CeMg
_chemical_formula_sum   'Ce2 Mg2'
_cell_volume   119.17
_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
  Ce  Ce0  1  0.91  0.0  0.26  1.0
  Ce  Ce1  1  0.0  0.74  0.43  1.0
  Mg  Mg2  1  0.0  0.0  0.39  1.0
  Mg  Mg3  1  0.91  0.74  0.3  1.0

data_CeMg
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.82
_cell_length_b   5.48
_cell_length_c   5.69
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   CeMg
_chemical_formula_sum   'Ce2 Mg2'
_cell_volume   119.17
_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
  Ce  Ce0  2  0.46  0.63  0.91  1.0
  Mg  Mg1  2  0.46  0.37  0.95  1.0

Ce Ce Mg Mg
Ce Ce Mg Mg 0 2 + o o 1 3 - o o 