Ir3Rh is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to four equivalent Ir(1), four equivalent Ir(2), and four equivalent Rh(1) atoms to form IrIr8Rh4 cuboctahedra that share corners with twelve equivalent Ir(1)Ir8Rh4 cuboctahedra, edges with eight equivalent Ir(1)Ir8Rh4 cuboctahedra, edges with eight equivalent Ir(2)Ir8Rh4 cuboctahedra, edges with eight equivalent Rh(1)Ir12 cuboctahedra, faces with four equivalent Ir(2)Ir8Rh4 cuboctahedra, faces with four equivalent Rh(1)Ir12 cuboctahedra, and faces with ten equivalent Ir(1)Ir8Rh4 cuboctahedra. In the second Ir site, Ir(2) is bonded to eight equivalent Ir(1) and four equivalent Rh(1) atoms to form IrIr8Rh4 cuboctahedra that share corners with four equivalent Ir(2)Ir8Rh4 cuboctahedra, corners with eight equivalent Rh(1)Ir12 cuboctahedra, edges with eight equivalent Ir(2)Ir8Rh4 cuboctahedra, edges with sixteen equivalent Ir(1)Ir8Rh4 cuboctahedra, faces with four equivalent Ir(2)Ir8Rh4 cuboctahedra, faces with six equivalent Rh(1)Ir12 cuboctahedra, and faces with eight equivalent Ir(1)Ir8Rh4 cuboctahedra. Rh(1) is bonded to four equivalent Ir(2) and eight equivalent Ir(1) atoms to form RhIr12 cuboctahedra that share corners with four equivalent Rh(1)Ir12 cuboctahedra, corners with eight equivalent Ir(2)Ir8Rh4 cuboctahedra, edges with eight equivalent Rh(1)Ir12 cuboctahedra, edges with sixteen equivalent Ir(1)Ir8Rh4 cuboctahedra, faces with four equivalent Rh(1)Ir12 cuboctahedra, faces with six equivalent Ir(2)Ir8Rh4 cuboctahedra, and faces with eight equivalent Ir(1)Ir8Rh4 cuboctahedra.
Ir3Rh is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Ir sites. In the first Ir site, Ir(1) is bonded to four equivalent Ir(1), four equivalent Ir(2), and four equivalent Rh(1) atoms to form IrIr8Rh4 cuboctahedra that share corners with twelve equivalent Ir(1)Ir8Rh4 cuboctahedra, edges with eight equivalent Ir(1)Ir8Rh4 cuboctahedra, edges with eight equivalent Ir(2)Ir8Rh4 cuboctahedra, edges with eight equivalent Rh(1)Ir12 cuboctahedra, faces with four equivalent Ir(2)Ir8Rh4 cuboctahedra, faces with four equivalent Rh(1)Ir12 cuboctahedra, and faces with ten equivalent Ir(1)Ir8Rh4 cuboctahedra. All Ir(1)-Ir(1) bond lengths are 2.71 Å. All Ir(1)-Ir(2) bond lengths are 2.72 Å. All Ir(1)-Rh(1) bond lengths are 2.72 Å. In the second Ir site, Ir(2) is bonded to eight equivalent Ir(1) and four equivalent Rh(1) atoms to form IrIr8Rh4 cuboctahedra that share corners with four equivalent Ir(2)Ir8Rh4 cuboctahedra, corners with eight equivalent Rh(1)Ir12 cuboctahedra, edges with eight equivalent Ir(2)Ir8Rh4 cuboctahedra, edges with sixteen equivalent Ir(1)Ir8Rh4 cuboctahedra, faces with four equivalent Ir(2)Ir8Rh4 cuboctahedra, faces with six equivalent Rh(1)Ir12 cuboctahedra, and faces with eight equivalent Ir(1)Ir8Rh4 cuboctahedra. All Ir(2)-Rh(1) bond lengths are 2.71 Å. Rh(1) is bonded to four equivalent Ir(2) and eight equivalent Ir(1) atoms to form RhIr12 cuboctahedra that share corners with four equivalent Rh(1)Ir12 cuboctahedra, corners with eight equivalent Ir(2)Ir8Rh4 cuboctahedra, edges with eight equivalent Rh(1)Ir12 cuboctahedra, edges with sixteen equivalent Ir(1)Ir8Rh4 cuboctahedra, faces with four equivalent Rh(1)Ir12 cuboctahedra, faces with six equivalent Ir(2)Ir8Rh4 cuboctahedra, and faces with eight equivalent Ir(1)Ir8Rh4 cuboctahedra.