CaIrO3 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2) and six equivalent O(1) atoms. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form a mixture of corner and edge-sharing IrO6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(1) and two equivalent Ir(1) atoms to form distorted OCa3Ir2 square pyramids that share corners with nine equivalent O(1)Ca3Ir2 square pyramids, corners with four equivalent O(2)Ca2Ir2 tetrahedra, edges with six equivalent O(1)Ca3Ir2 square pyramids, and edges with three equivalent O(2)Ca2Ir2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Ir(1) atoms to form distorted OCa2Ir2 tetrahedra that share corners with eight equivalent O(1)Ca3Ir2 square pyramids, corners with four equivalent O(2)Ca2Ir2 tetrahedra, and edges with six equivalent O(1)Ca3Ir2 square pyramids.
CaIrO3 crystallizes in the orthorhombic Cmcm space group. Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(2) and six equivalent O(1) atoms. Both Ca(1)-O(2) bond lengths are 2.32 Å. There are four shorter (2.47 Å) and two longer (2.53 Å) Ca(1)-O(1) bond lengths. Ir(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form a mixture of corner and edge-sharing IrO6 octahedra. The corner-sharing octahedral tilt angles are 46°. Both Ir(1)-O(2) bond lengths are 1.99 Å. All Ir(1)-O(1) bond lengths are 2.04 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Ca(1) and two equivalent Ir(1) atoms to form distorted OCa3Ir2 square pyramids that share corners with nine equivalent O(1)Ca3Ir2 square pyramids, corners with four equivalent O(2)Ca2Ir2 tetrahedra, edges with six equivalent O(1)Ca3Ir2 square pyramids, and edges with three equivalent O(2)Ca2Ir2 tetrahedra. In the second O site, O(2) is bonded to two equivalent Ca(1) and two equivalent Ir(1) atoms to form distorted OCa2Ir2 tetrahedra that share corners with eight equivalent O(1)Ca3Ir2 square pyramids, corners with four equivalent O(2)Ca2Ir2 tetrahedra, and edges with six equivalent O(1)Ca3Ir2 square pyramids.