data_[Ca2Mg2Hg8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  Mg  1.3100  1.5000  0.8600
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [10.2930]
_cell_length_b [3.9296]
_cell_length_c [7.6900]
_cell_angle_alpha [90.0000]
_cell_angle_beta [110.2171]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [CaMgHg4]
_chemical_formula_sum '[Ca2 Mg2 Hg8]'
_cell_volume [291.8775]
_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
[
  Ca  Ca0  2  0.0000  0.0000  0.0000  1
  Mg  Mg1  2  0.0000  0.0000  0.5000  1
  Hg  Hg2  4  0.1646  0.5000  0.3445  1
  Hg  Hg3  4  0.1648  0.5000  0.8159  1
]