data_[Mg18Hg3Pb36]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Hg  2.0000  1.5000  1.2450
  Pb  2.3300  1.8000  1.1225
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [15.4621]
_cell_length_b [15.4621]
_cell_length_c [7.9294]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Mg6HgPb12]
_chemical_formula_sum '[Mg18 Hg3 Pb36]'
_cell_volume [1641.7485]
_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
[
  Mg  Mg0  18  0.0166  0.1294  0.6754  1.0
  Hg  Hg1  3  0.0000  0.0000  0.0000  1.0
  Pb  Pb2  18  0.0314  0.2657  0.3541  1.0
  Pb  Pb3  18  0.0754  0.5656  0.6644  1.0
]