data_[Rb4Cu2Se6]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Cu  1.9000  1.3500  0.8200
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P-3m1]
_cell_length_a [7.0155]
_cell_length_b [7.0155]
_cell_length_c [12.0945]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [164]
_chemical_formula_structural [Rb2CuSe3]
_chemical_formula_sum '[Rb4 Cu2 Se6]'
_cell_volume [515.5104]
_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  0.3333  0.6667  0.7505  1
  Rb  Rb1  1  0.0000  0.0000  0.0000  1
  Rb  Rb2  1  0.0000  0.0000  0.5000  1
  Cu  Cu3  2  0.3333  0.6667  0.2439  1
  Se  Se4  6  0.1456  0.2912  0.2498  1
]