data_[Rb4Ta4Cu8Se16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Ta  1.5000  1.4500  0.8200
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Ama2]
_cell_length_a [7.8632]
_cell_length_b [19.6825]
_cell_length_c [5.7502]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [40]
_chemical_formula_structural [RbTa(CuSe2)2]
_chemical_formula_sum '[Rb4 Ta4 Cu8 Se16]'
_cell_volume [889.9500]
_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  0.2500  0.1838  0.3018  1
  Ta  Ta1  4  0.2500  0.3940  0.0446  1
  Cu  Cu2  4  0.0000  0.0000  0.5590  1
  Cu  Cu3  4  0.2500  0.3958  0.5441  1
  Se  Se4  8  0.0028  0.1048  0.7912  1
  Se  Se5  4  0.2500  0.2947  0.7957  1
  Se  Se6  4  0.2500  0.4970  0.7992  1
]