data_[Hg2Cl2O8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Hg  2.0000  1.5000  1.2450
  Cl  3.1600  1.0000  0.7800
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P-1]
_cell_length_a [3.6277]
_cell_length_b [8.2374]
_cell_length_c [9.1113]
_cell_angle_alpha [107.1284]
_cell_angle_beta [96.8704]
_cell_angle_gamma [98.6638]
_symmetry_Int_Tables_number [2]
_chemical_formula_structural [HgClO4]
_chemical_formula_sum '[Hg2 Cl2 O8]'
_cell_volume [253.3221]
_cell_formula_units_Z [2]
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  2  0.4868  0.4388  0.8210  1
  Cl  Cl1  2  0.0379  0.8693  0.5925  1
  O  O2  2  0.1091  0.9650  0.3549  1
  O  O3  2  0.2594  0.2927  0.4749  1
  O  O4  2  0.3071  0.8819  0.0322  1
  O  O5  2  0.4291  0.8504  0.9071  1
]