The crystal structure described by Rb3OI is (Cubic) Perovskite-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a linear geometry to one O(1), one O(2), one I(2), and three equivalent I(1) atoms. In the second Rb site, Rb(2) is bonded in a distorted L-shaped geometry to two equivalent O(1), two equivalent I(1), and two equivalent I(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Rb(1) and three equivalent Rb(2) atoms to form ORb6 octahedra that share corners with three equivalent I(1)Rb12 cuboctahedra, corners with three equivalent O(2)Rb6 octahedra, faces with three equivalent I(2)Rb12 cuboctahedra, faces with four equivalent I(1)Rb12 cuboctahedra, and  a faceface with one O(1)Rb6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second O site, O(2) is bonded to six equivalent Rb(1) atoms to form ORb6 octahedra that share corners with six equivalent O(1)Rb6 octahedra, faces with two equivalent I(2)Rb12 cuboctahedra, and faces with six equivalent I(1)Rb12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There are two inequivalent I sites. In the first I site, I(1) is bonded to three equivalent Rb(2) and nine equivalent Rb(1) atoms to form IRb12 cuboctahedra that share corners with three equivalent I(2)Rb12 cuboctahedra, corners with six equivalent I(1)Rb12 cuboctahedra, corners with three equivalent O(1)Rb6 octahedra, faces with three equivalent I(2)Rb12 cuboctahedra, faces with four equivalent I(1)Rb12 cuboctahedra, faces with three equivalent O(2)Rb6 octahedra, and faces with four equivalent O(1)Rb6 octahedra. The corner-sharing octahedral tilt angles are 10°. In the second I site, I(2) is bonded to six equivalent Rb(1) and six equivalent Rb(2) atoms to form IRb12 cuboctahedra that share corners with six equivalent I(1)Rb12 cuboctahedra, corners with six equivalent I(2)Rb12 cuboctahedra, faces with six equivalent I(1)Rb12 cuboctahedra, faces with two equivalent O(2)Rb6 octahedra, and faces with six equivalent O(1)Rb6 octahedra. is represented by the CIF file [CIF]
data_Rb3IO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.901
_cell_length_b   7.901
_cell_length_c   19.714
_cell_angle_alpha   90.002
_cell_angle_beta   89.997
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1065.864
_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  1  0.332  0.166  0.419  1.0
  Rb  Rb1  1  0.332  0.166  0.081  1.0
  Rb  Rb2  1  0.834  0.668  0.081  1.0
  Rb  Rb3  1  0.166  0.332  0.581  1.0
  Rb  Rb4  1  0.668  0.834  0.581  1.0
  Rb  Rb5  1  0.166  0.834  0.919  1.0
  Rb  Rb6  1  0.834  0.668  0.419  1.0
  Rb  Rb7  1  0.834  0.166  0.081  1.0
  Rb  Rb8  1  0.834  0.166  0.419  1.0
  Rb  Rb9  1  0.482  0.518  0.750  1.0
  Rb  Rb10  1  0.668  0.834  0.919  1.0
  Rb  Rb11  1  0.166  0.332  0.919  1.0
  Rb  Rb12  1  0.518  0.482  0.250  1.0
  Rb  Rb13  1  0.963  0.482  0.250  1.0
  Rb  Rb14  1  0.518  0.037  0.250  1.0
  Rb  Rb15  1  0.482  0.963  0.750  1.0
  Rb  Rb16  1  0.037  0.518  0.750  1.0
  Rb  Rb17  1  0.166  0.834  0.581  1.0
  I  I18  1  0.333  0.667  0.412  1.0
  I  I19  1  0.667  0.333  0.912  1.0
  I  I20  1  0.667  0.333  0.588  1.0
  I  I21  1  0.333  0.667  0.088  1.0
  I  I22  1  0.000  1.000  0.750  1.0
  I  I23  1  1.000  0.000  0.250  1.0
  O  O24  1  0.333  0.667  0.659  1.0
  O  O25  1  0.667  0.333  0.159  1.0
  O  O26  1  0.667  0.333  0.341  1.0
  O  O27  1  0.333  0.667  0.841  1.0
  O  O28  1  0.000  1.000  0.500  1.0
  O  O29  1  0.000  0.000  1.000  1.0
[/CIF]
.
The crystal structure described by Rb3OI is (Cubic) Perovskite-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a linear geometry to one O(1), one O(2), one I(2), and three equivalent I(1) atoms. In the second Rb site, Rb(2) is bonded in a distorted L-shaped geometry to two equivalent O(1), two equivalent I(1), and two equivalent I(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Rb(1) and three equivalent Rb(2) atoms to form ORb6 octahedra that share corners with three equivalent I(1)Rb12 cuboctahedra, corners with three equivalent O(2)Rb6 octahedra, faces with three equivalent I(2)Rb12 cuboctahedra, faces with four equivalent I(1)Rb12 cuboctahedra, and  a faceface with one O(1)Rb6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second O site, O(2) is bonded to six equivalent Rb(1) atoms to form ORb6 octahedra that share corners with six equivalent O(1)Rb6 octahedra, faces with two equivalent I(2)Rb12 cuboctahedra, and faces with six equivalent I(1)Rb12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There are two inequivalent I sites. In the first I site, I(1) is bonded to three equivalent Rb(2) and nine equivalent Rb(1) atoms to form IRb12 cuboctahedra that share corners with three equivalent I(2)Rb12 cuboctahedra, corners with six equivalent I(1)Rb12 cuboctahedra, corners with three equivalent O(1)Rb6 octahedra, faces with three equivalent I(2)Rb12 cuboctahedra, faces with four equivalent I(1)Rb12 cuboctahedra, faces with three equivalent O(2)Rb6 octahedra, and faces with four equivalent O(1)Rb6 octahedra. The corner-sharing octahedral tilt angles are 10°. In the second I site, I(2) is bonded to six equivalent Rb(1) and six equivalent Rb(2) atoms to form IRb12 cuboctahedra that share corners with six equivalent I(1)Rb12 cuboctahedra, corners with six equivalent I(2)Rb12 cuboctahedra, faces with six equivalent I(1)Rb12 cuboctahedra, faces with two equivalent O(2)Rb6 octahedra, and faces with six equivalent O(1)Rb6 octahedra. is represented by the CIF file [CIF]
data_Rb3IO
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.901
_cell_length_b   7.901
_cell_length_c   19.714
_cell_angle_alpha   90.002
_cell_angle_beta   89.997
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   1065.864
_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  1  0.332  0.166  0.419  1.0
  Rb  Rb1  1  0.332  0.166  0.081  1.0
  Rb  Rb2  1  0.834  0.668  0.081  1.0
  Rb  Rb3  1  0.166  0.332  0.581  1.0
  Rb  Rb4  1  0.668  0.834  0.581  1.0
  Rb  Rb5  1  0.166  0.834  0.919  1.0
  Rb  Rb6  1  0.834  0.668  0.419  1.0
  Rb  Rb7  1  0.834  0.166  0.081  1.0
  Rb  Rb8  1  0.834  0.166  0.419  1.0
  Rb  Rb9  1  0.482  0.518  0.750  1.0
  Rb  Rb10  1  0.668  0.834  0.919  1.0
  Rb  Rb11  1  0.166  0.332  0.919  1.0
  Rb  Rb12  1  0.518  0.482  0.250  1.0
  Rb  Rb13  1  0.963  0.482  0.250  1.0
  Rb  Rb14  1  0.518  0.037  0.250  1.0
  Rb  Rb15  1  0.482  0.963  0.750  1.0
  Rb  Rb16  1  0.037  0.518  0.750  1.0
  Rb  Rb17  1  0.166  0.834  0.581  1.0
  I  I18  1  0.333  0.667  0.412  1.0
  I  I19  1  0.667  0.333  0.912  1.0
  I  I20  1  0.667  0.333  0.588  1.0
  I  I21  1  0.333  0.667  0.088  1.0
  I  I22  1  0.000  1.000  0.750  1.0
  I  I23  1  1.000  0.000  0.250  1.0
  O  O24  1  0.333  0.667  0.659  1.0
  O  O25  1  0.667  0.333  0.159  1.0
  O  O26  1  0.667  0.333  0.341  1.0
  O  O27  1  0.333  0.667  0.841  1.0
  O  O28  1  0.000  1.000  0.500  1.0
  O  O29  1  0.000  0.000  1.000  1.0
[/CIF]
.