data_[Na4Sn12Hg8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Sn  1.9600  1.4500  0.8300
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [18.3885]
_cell_length_b [4.4804]
_cell_length_c [9.3512]
_cell_angle_alpha [90.0000]
_cell_angle_beta [118.7472]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [NaSn3Hg2]
_chemical_formula_sum '[Na4 Sn12 Hg8]'
_cell_volume [675.4616]
_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  4  0.1163  0.0000  0.1945  1.0
  Sn  Sn1  4  0.0771  0.0000  0.7010  1.0
  Sn  Sn2  4  0.0854  0.5000  0.4710  1.0
  Sn  Sn3  4  0.2210  0.5000  0.0588  1.0
  Hg  Hg4  4  0.0356  0.5000  0.8886  1.0
  Hg  Hg5  4  0.2303  0.0000  0.5891  1.0
]