data_[Rb12Na20Hg8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Na  0.9300  1.8000  1.1600
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [Ibam]
_cell_length_a [14.5258]
_cell_length_b [16.1711]
_cell_length_c [7.9086]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [72]
_chemical_formula_structural [Rb3Na5Hg2]
_chemical_formula_sum '[Rb12 Na20 Hg8]'
_cell_volume [1857.7211]
_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
[
  Rb  Rb0  8  0.2398  0.1444  0.0000  1.0
  Rb  Rb1  4  0.0000  0.0000  0.2500  1.0
  Na  Na2  8  0.0000  0.2654  0.2500  1.0
  Na  Na3  8  0.1665  0.3975  0.0000  1.0
  Na  Na4  4  0.0000  0.5000  0.2500  1.0
  Hg  Hg5  8  0.1308  0.1580  0.5000  1.0
]