IrRh3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ir(1) is bonded to four equivalent Rh(2) and eight equivalent Rh(1) atoms to form IrRh12 cuboctahedra that share corners with four equivalent Ir(1)Rh12 cuboctahedra, corners with eight equivalent Rh(2)Ir4Rh8 cuboctahedra, edges with eight equivalent Ir(1)Rh12 cuboctahedra, edges with sixteen equivalent Rh(1)Ir4Rh8 cuboctahedra, faces with four equivalent Ir(1)Rh12 cuboctahedra, faces with six equivalent Rh(2)Ir4Rh8 cuboctahedra, and faces with eight equivalent Rh(1)Ir4Rh8 cuboctahedra. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to four equivalent Ir(1), four equivalent Rh(1), and four equivalent Rh(2) atoms to form RhIr4Rh8 cuboctahedra that share corners with twelve equivalent Rh(1)Ir4Rh8 cuboctahedra, edges with eight equivalent Ir(1)Rh12 cuboctahedra, edges with eight equivalent Rh(1)Ir4Rh8 cuboctahedra, edges with eight equivalent Rh(2)Ir4Rh8 cuboctahedra, faces with four equivalent Ir(1)Rh12 cuboctahedra, faces with four equivalent Rh(2)Ir4Rh8 cuboctahedra, and faces with ten equivalent Rh(1)Ir4Rh8 cuboctahedra. In the second Rh site, Rh(2) is bonded to four equivalent Ir(1) and eight equivalent Rh(1) atoms to form RhIr4Rh8 cuboctahedra that share corners with four equivalent Rh(2)Ir4Rh8 cuboctahedra, corners with eight equivalent Ir(1)Rh12 cuboctahedra, edges with eight equivalent Rh(2)Ir4Rh8 cuboctahedra, edges with sixteen equivalent Rh(1)Ir4Rh8 cuboctahedra, faces with four equivalent Rh(2)Ir4Rh8 cuboctahedra, faces with six equivalent Ir(1)Rh12 cuboctahedra, and faces with eight equivalent Rh(1)Ir4Rh8 cuboctahedra.
IrRh3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. Ir(1) is bonded to four equivalent Rh(2) and eight equivalent Rh(1) atoms to form IrRh12 cuboctahedra that share corners with four equivalent Ir(1)Rh12 cuboctahedra, corners with eight equivalent Rh(2)Ir4Rh8 cuboctahedra, edges with eight equivalent Ir(1)Rh12 cuboctahedra, edges with sixteen equivalent Rh(1)Ir4Rh8 cuboctahedra, faces with four equivalent Ir(1)Rh12 cuboctahedra, faces with six equivalent Rh(2)Ir4Rh8 cuboctahedra, and faces with eight equivalent Rh(1)Ir4Rh8 cuboctahedra. All Ir(1)-Rh(2) bond lengths are 2.70 Å. All Ir(1)-Rh(1) bond lengths are 2.70 Å. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to four equivalent Ir(1), four equivalent Rh(1), and four equivalent Rh(2) atoms to form RhIr4Rh8 cuboctahedra that share corners with twelve equivalent Rh(1)Ir4Rh8 cuboctahedra, edges with eight equivalent Ir(1)Rh12 cuboctahedra, edges with eight equivalent Rh(1)Ir4Rh8 cuboctahedra, edges with eight equivalent Rh(2)Ir4Rh8 cuboctahedra, faces with four equivalent Ir(1)Rh12 cuboctahedra, faces with four equivalent Rh(2)Ir4Rh8 cuboctahedra, and faces with ten equivalent Rh(1)Ir4Rh8 cuboctahedra. All Rh(1)-Rh(1) bond lengths are 2.70 Å. All Rh(1)-Rh(2) bond lengths are 2.70 Å. In the second Rh site, Rh(2) is bonded to four equivalent Ir(1) and eight equivalent Rh(1) atoms to form RhIr4Rh8 cuboctahedra that share corners with four equivalent Rh(2)Ir4Rh8 cuboctahedra, corners with eight equivalent Ir(1)Rh12 cuboctahedra, edges with eight equivalent Rh(2)Ir4Rh8 cuboctahedra, edges with sixteen equivalent Rh(1)Ir4Rh8 cuboctahedra, faces with four equivalent Rh(2)Ir4Rh8 cuboctahedra, faces with six equivalent Ir(1)Rh12 cuboctahedra, and faces with eight equivalent Rh(1)Ir4Rh8 cuboctahedra.