data_Rb2O3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.87
_cell_length_b   7.87
_cell_length_c   7.87
_cell_angle_alpha   109.47
_cell_angle_beta   109.47
_cell_angle_gamma   109.47
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Rb2O3
_chemical_formula_sum   'Rb8 O12'
_cell_volume   375.42
_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  Rb12  1  0.05  0.49  0.51  1.0
  Rb  Rb13  1  0.33  0.22  0.78  1.0
  Rb  Rb14  1  0.76  0.76  0.76  1.0
  Rb  Rb15  1  0.78  0.33  0.22  1.0
  Rb  Rb16  1  0.22  0.78  0.33  1.0
  Rb  Rb17  1  0.49  0.51  0.05  1.0
  Rb  Rb18  1  0.49  0.49  0.49  1.0
  Rb  Rb19  1  0.51  0.05  0.49  1.0
  O  O0  1  0.27  0.71  0.0  1.0
  O  O1  1  0.27  0.11  0.0  1.0
  O  O2  1  0.0  0.82  0.44  1.0
  O  O3  1  0.0  0.82  0.84  1.0
  O  O4  1  0.82  0.44  0.0  1.0
  O  O5  1  0.82  0.84  0.0  1.0
  O  O6  1  0.44  0.0  0.82  1.0
  O  O7  1  0.84  0.0  0.82  1.0
  O  O8  1  0.0  0.27  0.71  1.0
  O  O9  1  0.0  0.27  0.11  1.0
  O  O10  1  0.71  0.0  0.27  1.0
  O  O11  1  0.11  0.0  0.27  1.0

data_Rb2O3
_symmetry_space_group_name_H-M   R3
_cell_length_a   12.85
_cell_length_b   12.85
_cell_length_c   7.87
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   Rb2O3
_chemical_formula_sum   'Rb24 O36'
_cell_volume   1126.25
_cell_formula_units_Z   12
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  'x+2/3, y+1/3, z+1/3'
  5  '-y+2/3, x-y+1/3, z+1/3'
  6  '-x+y+2/3, -x+1/3, z+1/3'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
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  9  0.01  0.56  0.78  1.0
  Rb  Rb1  9  0.04  0.51  0.02  1.0
  Rb  Rb2  3  0.0  0.0  0.49  1.0
  Rb  Rb3  3  0.0  0.0  0.76  1.0
  O  O4  9  0.01  0.29  0.99  1.0
  O  O5  9  0.02  0.6  0.42  1.0
  O  O6  9  0.12  0.05  0.88  1.0
  O  O7  9  0.15  0.13  0.13  1.0

Rb Rb Rb Rb Rb Rb Rb Rb O O O O O O O O O O O O
Rb Rb Rb Rb Rb Rb Rb Rb O O O O O O O O O O O O 0 3 - o o 0 8 o o + 0 16 o o o 0 18 - o o 1 9 o o + 1 14 o o o 1 5 o o + 1 16 o o o 2 15 o + o 2 11 + o o 2 13 o o + 2 6 o o o 3 12 o o o 3 17 + o o 3 18 o o o 4 19 o + o 4 10 o o o 4 7 o + o 4 8 o o o 5 8 o o o 5 16 o o - 5 18 o + o 7 8 o - o 7 16 + o o 7 18 o o o 8 16 o o - 8 9 o + o 8 11 o o - 8 14 o + - 8 18 o + o 9 11 o - - 9 14 o o - 10 19 o + o 10 18 - + o 12 17 + o o 12 16 + o - 13 18 o + o 13 19 + + o 15 16 + o o 15 17 + o + 16 18 - o o 16 17 o o + 18 19 + o o 
Rb2O3 crystallizes in the trigonal R3 space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 1-coordinate geometry to one Rb(2) and one O(1) atom. The Rb(1)-Rb(2) bond length is 2.10 Å. The Rb(1)-O(1) bond length is 2.71 Å. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one Rb(1), one O(1), two equivalent O(2), and three equivalent O(3) atoms. The Rb(2)-O(1) bond length is 2.65 Å. There is one shorter (2.26 Å) and one longer (3.29 Å) Rb(2)-O(2) bond length. There are a spread of Rb(2)-O(3) bond distances ranging from 2.22-3.16 Å. In the third Rb site, Rb(3) is bonded in a 3-coordinate geometry to one Rb(4) and three equivalent O(4) atoms. The Rb(3)-Rb(4) bond length is 2.14 Å. All Rb(3)-O(4) bond lengths are 1.61 Å. In the fourth Rb site, Rb(4) is bonded in a 4-coordinate geometry to one Rb(3) and three equivalent O(2) atoms. All Rb(4)-O(2) bond lengths are 3.36 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Rb(1) and one Rb(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Rb(4) and two equivalent Rb(2) atoms. In the third O site, O(3) is bonded in a 1-coordinate geometry to three equivalent Rb(2) atoms. In the fourth O site, O(4) is bonded in a single-bond geometry to one Rb(3) atom.