data_[Mg4Hg4Se4O4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  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 [Pnma]
_cell_length_a [5.6866]
_cell_length_b [3.6464]
_cell_length_c [14.6111]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [62]
_chemical_formula_structural [MgHgSeO]
_chemical_formula_sum '[Mg4 Hg4 Se4 O4]'
_cell_volume [302.9666]
_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
[
  Mg  Mg0  4  0.2345  0.2500  0.4003  1
  Hg  Hg1  4  0.2190  0.7500  0.1931  1
  Se  Se2  4  0.2489  0.7500  0.5628  1
  O  O3  4  0.2494  0.7500  0.3416  1
]