data_[Na8Hg4I20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Hg  2.0000  1.5000  1.2450
  I  2.6600  1.4000  1.2733
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [6.4580]
_cell_length_b [15.5901]
_cell_length_c [13.1732]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [Na2HgI5]
_chemical_formula_sum '[Na8 Hg4 I20]'
_cell_volume [1326.2979]
_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
[
  Na  Na0  8  0.0000  0.1753  0.5762  1
  Hg  Hg1  4  0.0000  0.1995  0.2500  1
  I  I2  8  0.0000  0.0301  0.1178  1
  I  I3  8  0.0000  0.3223  0.0851  1
  I  I4  4  0.0000  0.3092  0.7500  1
]