Cr2Ir2O5 crystallizes in the tetragonal P4/mmm space group. Cr(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. In the second Ir site, Ir(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Cr(1) and two equivalent Ir(1) atoms to form OCr2Ir2 tetrahedra that share corners with two equivalent O(2)Cr2Ir4 octahedra, corners with ten equivalent O(1)Cr2Ir2 tetrahedra, and edges with five equivalent O(1)Cr2Ir2 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the second O site, O(2) is bonded to two equivalent Cr(1) and four equivalent Ir(2) atoms to form OCr2Ir4 octahedra that share corners with four equivalent O(2)Cr2Ir4 octahedra, corners with eight equivalent O(1)Cr2Ir2 tetrahedra, and edges with four equivalent O(2)Cr2Ir4 octahedra. The corner-sharing octahedra are not tilted.
Cr2Ir2O5 crystallizes in the tetragonal P4/mmm space group. Cr(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. The Cr(1)-O(2) bond length is 2.00 Å. All Cr(1)-O(1) bond lengths are 2.09 Å. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. All Ir(1)-O(1) bond lengths are 2.10 Å. In the second Ir site, Ir(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Ir(2)-O(2) bond lengths are 2.42 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Cr(1) and two equivalent Ir(1) atoms to form OCr2Ir2 tetrahedra that share corners with two equivalent O(2)Cr2Ir4 octahedra, corners with ten equivalent O(1)Cr2Ir2 tetrahedra, and edges with five equivalent O(1)Cr2Ir2 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the second O site, O(2) is bonded to two equivalent Cr(1) and four equivalent Ir(2) atoms to form OCr2Ir4 octahedra that share corners with four equivalent O(2)Cr2Ir4 octahedra, corners with eight equivalent O(1)Cr2Ir2 tetrahedra, and edges with four equivalent O(2)Cr2Ir4 octahedra. The corner-sharing octahedra are not tilted.