data_[Rb4Ca4Hg8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Ca  1.0000  1.8000  1.1400
  Hg  2.0000  1.5000  1.2450
]
_symmetry_space_group_name_H-M [I-42d]
_cell_length_a [8.9466]
_cell_length_b [8.9466]
_cell_length_c [7.8172]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [122]
_chemical_formula_structural [RbCaHg2]
_chemical_formula_sum '[Rb4 Ca4 Hg8]'
_cell_volume [625.7116]
_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
[
  Rb  Rb0  4  0.0000  0.0000  0.0000  1
  Ca  Ca1  4  0.0000  0.0000  0.5000  1
  Hg  Hg2  8  0.2135  0.7500  0.6250  1
]