data_[Hg54Sb18I18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Hg  2.0000  1.5000  1.2450
  Sb  2.0500  1.4500  0.8300
  I  2.6600  1.4000  1.2733
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [18.4445]
_cell_length_b [18.4445]
_cell_length_c [12.0676]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Hg3SbI]
_chemical_formula_sum '[Hg54 Sb18 I18]'
_cell_volume [3555.3732]
_cell_formula_units_Z [18]
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
[
  Hg  Hg0  18  0.0079  0.2781  0.3554  1
  Hg  Hg1  18  0.0493  0.8378  0.1378  1
  Hg  Hg2  18  0.0935  0.5435  0.2865  1
  Sb  Sb3  18  0.0561  0.8198  0.3627  1
  I  I4  18  0.0488  0.8341  0.9043  1
]