data_[Rb3Tl6Cr6O21]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Tl  1.6200  1.9000  1.3325
  Cr  1.6600  1.4000  0.9400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R32]
_cell_length_a [6.0732]
_cell_length_b [6.0732]
_cell_length_c [24.4142]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [155]
_chemical_formula_structural [RbTl2Cr2O7]
_chemical_formula_sum '[Rb3 Tl6 Cr6 O21]'
_cell_volume [779.8451]
_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
[
  Rb  Rb0  3  0.0000  0.0000  0.5000  1
  Tl  Tl1  6  0.0000  0.0000  0.2969  1
  Cr  Cr2  6  0.0000  0.0000  0.0730  1
  O  O3  18  0.0438  0.2818  0.9062  1
  O  O4  3  0.0000  0.0000  0.0000  1
]