data_[Rb6Er3Si6O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  Er  1.2400  1.7500  1.0300
  Si  1.9000  1.1000  0.5400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [5.9156]
_cell_length_b [5.9156]
_cell_length_c [17.7405]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [Rb2Er(SiO3)2]
_chemical_formula_sum '[Rb6 Er3 Si6 O18]'
_cell_volume [537.6496]
_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  6  0.0000  0.0000  0.2819  1
  Er  Er1  3  -0.0000  -0.0000  0.5000  1
  Si  Si2  6  0.0000  0.0000  0.0742  1
  O  O3  18  0.0229  0.5115  0.7588  1
]