data_[Pm20Mg8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Pm  1.1300  1.8500  1.1100
  Mg  1.3100  1.5000  0.8600
]
_symmetry_space_group_name_H-M [Cccm]
_cell_length_a [8.1144]
_cell_length_b [15.6289]
_cell_length_c [7.0882]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [66]
_chemical_formula_structural [Pm5Mg2]
_chemical_formula_sum '[Pm20 Mg8]'
_cell_volume [898.9192]
_cell_formula_units_Z [4]
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
[
  Pm  Pm0  8  0.0000  0.2672  0.2500  1
  Pm  Pm1  8  0.1796  0.0955  0.5000  1
  Pm  Pm2  4  0.0000  0.5000  0.2500  1
  Mg  Mg3  8  0.2274  0.8795  0.5000  1
]