data_IrO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.94
_cell_length_b   4.94
_cell_length_c   4.94
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   IrO2
_chemical_formula_sum   'Ir4 O8'
_cell_volume   120.74
_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
  Ir  Ir0  1  0.47  0.47  0.0  1.0
  Ir  Ir1  1  0.47  0.0  0.47  1.0
  Ir  Ir2  1  0.0  0.47  0.47  1.0
  Ir  Ir3  1  0.0  0.0  0.0  1.0
  O  O4  1  0.75  0.19  0.72  1.0
  O  O5  1  0.19  0.72  0.75  1.0
  O  O6  1  0.72  0.75  0.19  1.0
  O  O7  1  0.22  0.22  0.22  1.0
  O  O8  1  0.19  0.75  0.22  1.0
  O  O9  1  0.75  0.22  0.19  1.0
  O  O10  1  0.22  0.19  0.75  1.0
  O  O11  1  0.72  0.72  0.72  1.0

data_IrO2
_symmetry_space_group_name_H-M   R3
_cell_length_a   6.99
_cell_length_b   6.99
_cell_length_c   8.56
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   IrO2
_chemical_formula_sum   'Ir12 O24'
_cell_volume   362.23
_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+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
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
  Ir  Ir0  9  0.02  0.51  0.98  1.0
  Ir  Ir1  3  0.0  0.0  -0.0  1.0
  O  O2  9  0.03  0.53  0.72  1.0
  O  O3  9  0.17  0.36  0.55  1.0
  O  O4  3  0.0  0.0  0.22  1.0
  O  O5  3  0.0  0.0  0.72  1.0

Ir Ir Ir Ir O O O O O O O O
Ir Ir Ir Ir O O O O O O O O 0 10 o o - 0 7 o o o 0 5 o o - 0 8 o o o 0 4 o o - 0 9 o o o 0 11 o o - 0 6 o o o 1 8 o - o 1 5 o - o 1 7 o o o 1 10 o o o 1 6 o - o 1 11 o - o 1 9 o o o 1 4 o o o 2 9 - o o 2 4 - o o 2 6 - o o 2 11 - o o 2 7 o o o 2 10 o o o 2 8 o o o 2 5 o o o 3 6 - - o 3 4 - o - 3 9 - o o 3 5 o - - 3 8 o - o 3 10 o o - 3 7 o o o 3 11 - - - 4 11 o - o 4 11 o o o 4 10 o o o 4 10 + o o 4 9 o o o 4 9 o o + 5 11 - o o 5 11 o o o 5 10 o o o 5 10 o + o 5 8 o o o 5 8 o o + 6 8 o o o 6 8 + o o 6 11 o o - 6 11 o o o 6 9 o o o 6 9 o + o 7 8 o - o 7 9 - o o 7 10 o o - 
IrO2 is Fluorite structured and crystallizes in the trigonal R3 space group. There are five inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a body-centered cubic geometry to one O(2), one O(4), three equivalent O(1), and three equivalent O(3) atoms. The Ir(1)-O(2) bond length is 2.05 Å. The Ir(1)-O(4) bond length is 2.22 Å. There are a spread of Ir(1)-O(1) bond distances ranging from 2.08-2.40 Å. There are a spread of Ir(1)-O(3) bond distances ranging from 2.08-2.25 Å. In the second Ir site, Ir(1) is bonded in a body-centered cubic geometry to one O(2); one O(4); three O(1,1); and three equivalent O(3) atoms. The Ir(1)-O(2) bond length is 2.05 Å. The Ir(1)-O(4) bond length is 2.22 Å. There are a spread of Ir(1)-O(1,1) bond distances ranging from 2.08-2.40 Å. There are a spread of Ir(1)-O(3) bond distances ranging from 2.08-2.25 Å. In the third Ir site, Ir(2) is bonded in a distorted body-centered cubic geometry to one O(2); one O(4); three O(1,1,1); and three equivalent O(3) atoms. The Ir(2)-O(2) bond length is 1.91 Å. The Ir(2)-O(4) bond length is 2.40 Å. All Ir(2)-O(1,1,1) bond lengths are 2.08 Å. All Ir(2)-O(3) bond lengths are 1.90 Å. In the fourth Ir site, Ir(1) is bonded in a body-centered cubic geometry to one O(2); one O(4); three O(1,1,1); and three equivalent O(3) atoms. The Ir(1)-O(2) bond length is 2.05 Å. The Ir(1)-O(4) bond length is 2.22 Å. There are a spread of Ir(1)-O(1,1,1) bond distances ranging from 2.08-2.40 Å. There are a spread of Ir(1)-O(3) bond distances ranging from 2.08-2.25 Å. In the fifth Ir site, Ir(1) is bonded in a body-centered cubic geometry to one O(2); one O(4); three O(1,1,1); and three equivalent O(3) atoms. The Ir(1)-O(2) bond length is 2.05 Å. The Ir(1)-O(4) bond length is 2.22 Å. There are a spread of Ir(1)-O(1,1,1) bond distances ranging from 2.08-2.40 Å. There are a spread of Ir(1)-O(3) bond distances ranging from 2.08-2.25 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Ir(2) and three Ir(1,1) atoms to form a mixture of edge and corner-sharing OIr4 tetrahedra. In the second O site, O(1) is bonded to one Ir(2) and three Ir(1,1) atoms to form a mixture of edge and corner-sharing OIr4 tetrahedra. The O(1)-Ir(2) bond length is 2.08 Å. There is one shorter (2.08 Å) and one longer (2.22 Å) O(1)-Ir(1) bond length. In the third O site, O(1) is bonded to one Ir(2) and three Ir(1,1,1) atoms to form a mixture of edge and corner-sharing OIr4 tetrahedra. In the fourth O site, O(2) is bonded to one Ir(2) and three Ir(1,1) atoms to form a mixture of edge and corner-sharing OIr4 tetrahedra. In the fifth O site, O(3) is bonded to one Ir(2) and three Ir(1,1,1) atoms to form a mixture of edge and corner-sharing OIr4 tetrahedra. In the sixth O site, O(4) is bonded to one Ir(2) and three Ir(1,1,1) atoms to form a mixture of edge and corner-sharing OIr4 tetrahedra. In the seventh O site, O(1) is bonded to one Ir(2) and three Ir(1,1) atoms to form a mixture of edge and corner-sharing OIr4 tetrahedra. There is one shorter (2.22 Å) and one longer (2.40 Å) O(1)-Ir(1) bond length.