Sr5(IrO3)6 crystallizes in the cubic Im-3 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(1) atoms. In the second Sr site, Sr(2) is bonded to six equivalent O(2) atoms to form SrO6 octahedra that share corners with twelve equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form IrO6 octahedra that share corners with two equivalent Sr(2)O6 octahedra, corners with four equivalent Ir(1)O6 octahedra, and  an edgeedge with one Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Ir(1) atoms. In the second O site, O(2) is bonded in a distorted L-shaped geometry to one Sr(2) and two equivalent Ir(1) atoms.
Sr5(IrO3)6 crystallizes in the cubic Im-3 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a distorted hexagonal planar geometry to six equivalent O(1) atoms. All Sr(1)-O(1) bond lengths are 2.51 Å. In the second Sr site, Sr(2) is bonded to six equivalent O(2) atoms to form SrO6 octahedra that share corners with twelve equivalent Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. All Sr(2)-O(2) bond lengths are 3.27 Å. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form IrO6 octahedra that share corners with two equivalent Sr(2)O6 octahedra, corners with four equivalent Ir(1)O6 octahedra, and  an edgeedge with one Ir(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-54°. Both Ir(1)-O(2) bond lengths are 2.04 Å. There are two shorter (1.99 Å) and two longer (2.00 Å) Ir(1)-O(1) bond lengths. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1) and two equivalent Ir(1) atoms. In the second O site, O(2) is bonded in a distorted L-shaped geometry to one Sr(2) and two equivalent Ir(1) atoms.