data_[Tb21Si3I36]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Tb  1.1000  1.7500  0.9815
  Si  1.9000  1.1000  0.5400
  I  2.6600  1.4000  1.2733
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [15.7347]
_cell_length_b [15.7347]
_cell_length_c [10.4813]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Tb7SiI12]
_chemical_formula_sum '[Tb21 Si3 I36]'
_cell_volume [2247.2997]
_cell_formula_units_Z [3]
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
[
  Tb  Tb0  18  0.0453  0.8842  0.8527  1.0
  Tb  Tb1  3  0.0000  0.0000  0.5000  1.0
  Si  Si2  3  0.0000  0.0000  0.0000  1.0
  I  I3  18  0.0218  0.4352  0.6642  1.0
  I  I4  18  0.0512  0.8690  0.3369  1.0
]