data_[Na36Mg3Pb21]
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 [R-3]
_cell_length_a [19.0237]
_cell_length_b [19.0237]
_cell_length_c [6.5456]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Na12MgPb7]
_chemical_formula_sum '[Na36 Mg3 Pb21]'
_cell_volume [2051.4875]
_cell_formula_units_Z [3]
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  18  0.0240  0.5967  0.6024  1.0
  Na  Na1  18  0.0699  0.2007  0.3581  1.0
  Mg  Mg2  3  0.0000  0.0000  0.0000  1.0
  Pb  Pb3  18  0.0500  0.1721  0.8579  1.0
  Pb  Pb4  3  0.0000  0.0000  0.5000  1.0
]