data_[Na12Sn4Hg28]
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 [Cmcm]
_cell_length_a [3.7189]
_cell_length_b [24.3999]
_cell_length_c [12.9410]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [Na3SnHg7]
_chemical_formula_sum '[Na12 Sn4 Hg28]'
_cell_volume [1174.2630]
_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  0.0797  0.0368  1
  Na  Na1  4  0.0000  0.2405  0.7500  1
  Sn  Sn2  4  0.0000  0.0997  0.7500  1
  Hg  Hg3  8  0.0000  0.2058  0.0826  1
  Hg  Hg4  8  0.0000  0.3365  0.0971  1
  Hg  Hg5  8  0.0000  0.4896  0.1294  1
  Hg  Hg6  4  0.0000  0.3795  0.7500  1
]