data_[Na4Er4Hg16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Er  1.2400  1.7500  1.0300
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [4.6428]
_cell_length_b [14.8917]
_cell_length_c [8.6936]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [NaErHg4]
_chemical_formula_sum '[Na4 Er4 Hg16]'
_cell_volume [601.0746]
_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
[
  Na  Na0  4  0.0000  0.1505  0.2500  1.0
  Er  Er1  4  0.0000  0.1582  0.7500  1.0
  Hg  Hg2  8  0.0000  0.3232  0.5035  1.0
  Hg  Hg3  4  0.0000  0.0000  0.0000  1.0
  Hg  Hg4  4  0.0000  0.4935  0.2500  1.0
]