data_[Rb4Na12Hg8]
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 [C2/m]
_cell_length_a [18.9940]
_cell_length_b [5.1267]
_cell_length_c [10.0274]
_cell_angle_alpha [90.0000]
_cell_angle_beta [115.9331]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [RbNa3Hg2]
_chemical_formula_sum '[Rb4 Na12 Hg8]'
_cell_volume [878.1082]
_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  4  0.1518  0.0000  0.0656  1
  Na  Na1  4  0.0419  0.0000  0.3680  1
  Na  Na2  4  0.0925  0.5000  0.6857  1
  Na  Na3  4  0.1855  0.5000  0.4551  1
  Hg  Hg4  4  0.0228  0.5000  0.1618  1
  Hg  Hg5  4  0.1908  0.0000  0.6873  1
]