data_[Na6Mg8Pb8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Mg  1.3100  1.5000  0.8600
  Pb  2.3300  1.8000  1.1225
]
_symmetry_space_group_name_H-M [Immm]
_cell_length_a [4.7652]
_cell_length_b [8.2792]
_cell_length_c [16.0540]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [71]
_chemical_formula_structural [Na3(MgPb)4]
_chemical_formula_sum '[Na6 Mg8 Pb8]'
_cell_volume [633.3656]
_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
[
  Na  Na0  4  0.0000  0.0000  0.1192  1.0
  Na  Na1  2  0.0000  0.5000  0.0000  1.0
  Mg  Mg2  8  0.0000  0.2004  0.6751  1.0
  Pb  Pb3  4  0.0000  0.3103  0.5000  1.0
  Pb  Pb4  4  0.0000  0.5000  0.2166  1.0
]