data_[Si8Hg4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Si  1.9000  1.1000  0.5400
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [3.0218]
_cell_length_b [21.8904]
_cell_length_c [3.6202]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [Si2Hg]
_chemical_formula_sum '[Si8 Hg4]'
_cell_volume [239.4665]
_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
[
  Si  Si0  4  0.0000  0.2701  0.2500  1
  Si  Si1  4  0.0000  0.4638  0.7500  1
  Hg  Hg2  4  0.0000  0.1212  0.7500  1
]