data_[Ce1Er2Hg4]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ce  1.1200  1.8500  1.0800
  Er  1.2400  1.7500  1.0300
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [P4/mmm]
_cell_length_a [5.2191]
_cell_length_b [5.2191]
_cell_length_c [7.2052]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [123]
_chemical_formula_structural [Ce(ErHg2)2]
_chemical_formula_sum '[Ce1 Er2 Hg4]'
_cell_volume [196.2622]
_cell_formula_units_Z [1]
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
[
  Ce  Ce0  1  0.5000  0.5000  0.0000  1
  Er  Er1  1  0.0000  0.0000  0.0000  1
  Er  Er2  1  0.5000  0.5000  0.5000  1
  Hg  Hg3  4  0.0000  0.5000  0.2695  1
]