data_[Rb2Ca2Tl2I8]
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
  Tl  1.6200  1.9000  1.3325
  I  2.6600  1.4000  1.2733
]
_symmetry_space_group_name_H-M [I4mm]
_cell_length_a [6.1616]
_cell_length_b [6.1616]
_cell_length_c [18.1415]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [107]
_chemical_formula_structural [RbCaTlI4]
_chemical_formula_sum '[Rb2 Ca2 Tl2 I8]'
_cell_volume [688.7502]
_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
[
  Rb  Rb0  2  0.0000  0.0000  0.6353  1.0
  Ca  Ca1  2  0.0000  0.0000  0.0003  1.0
  Tl  Tl2  2  0.0000  0.0000  0.3598  1.0
  I  I3  4  0.0000  0.5000  0.4995  1.0
  I  I4  2  0.0000  0.0000  0.1748  1.0
  I  I5  2  0.0000  0.0000  0.8308  1.0
]