data_[Rb6Cu12Se18]
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 [R-3m]
_cell_length_a [7.1681]
_cell_length_b [7.1681]
_cell_length_c [21.5463]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [RbCu2Se3]
_chemical_formula_sum '[Rb6 Cu12 Se18]'
_cell_volume [958.7713]
_cell_formula_units_Z [6]
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  6  0.0000  0.0000  0.1950  1
  Cu  Cu1  9  0.0000  0.5000  0.0000  1
  Cu  Cu2  3  0.0000  0.0000  0.0000  1
  Se  Se3  18  0.0083  0.5041  0.2727  1
]