data_[Rb4Er2Cu4O8]
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
  Cu  1.9000  1.3500  0.8200
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [13.4714]
_cell_length_b [3.4447]
_cell_length_c [6.6578]
_cell_angle_alpha [90.0000]
_cell_angle_beta [107.2743]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Rb2Er(CuO2)2]
_chemical_formula_sum '[Rb4 Er2 Cu4 O8]'
_cell_volume [295.0174]
_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  4  0.1290  0.0000  0.5534  1
  Er  Er1  2  0.0000  0.0000  0.0000  1
  Cu  Cu2  4  0.1817  0.5000  0.0288  1
  O  O3  4  0.0311  0.5000  0.8024  1
  O  O4  4  0.1827  0.0000  0.1607  1
]