data_[Si2Hg2Se4O16]
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
  Se  2.5500  1.1500  1.0133
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [8.0747]
_cell_length_b [5.1636]
_cell_length_c [10.4069]
_cell_angle_alpha [90.0000]
_cell_angle_beta [103.8937]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [SiHg(SeO4)2]
_chemical_formula_sum '[Si2 Hg2 Se4 O16]'
_cell_volume [421.2175]
_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
[
  Si  Si0  2  0.0000  0.0000  0.0000  1
  Hg  Hg1  2  0.0000  0.5000  0.5000  1
  Se  Se2  4  0.1970  0.5000  0.1551  1
  O  O3  8  0.0598  0.2419  0.1291  1
  O  O4  4  0.1812  0.0000  0.6979  1
  O  O5  4  0.2107  0.0000  0.9775  1
]