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IrPb crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Ir is bonded in a 8-coordinate geometry to two equivalent Ir and six equivalent Pb atoms. Both Ir–Ir bond lengths are 2.84 Å. All Ir–Pb bond lengths are 2.81 Å. Pb is bonded in a 6-coordinate geometry to six equivalent Ir atoms.
Ir3Pb is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Ir sites. In the first Ir site, Ir is bonded to eight Ir and four equivalent Pb atoms to form IrIr8Pb4 cuboctahedra that share corners with twelve equivalent IrIr8Pb4 cuboctahedra, edges with eight equivalent PbIr12 cuboctahedra, edges with sixteen IrIr8Pb4 cuboctahedra, faces with four equivalent PbIr12 cuboctahedra, and faces with fourteen IrIr8Pb4 cuboctahedra. There are four shorter (2.84 Å) and four longer (2.91 Å) Ir–Ir bond lengths. All Ir–Pb bond lengths are 2.84 Å. In the second Ir site, Ir is bonded to eight equivalent Ir and four equivalent Pb atoms to form IrIr8Pb4 cuboctahedra that share corners with four equivalent IrIr8Pb4 cuboctahedra, corners with eight equivalent PbIr12 cuboctahedra, edges with twenty-four IrIr8Pb4 cuboctahedra, faces with six equivalent PbIr12 cuboctahedra, and faces with twelve IrIr8Pb4 cuboctahedra. All Ir–Pb bond lengths are 2.91 Å. Pb is bonded to twelve Ir atoms to form PbIr12 cuboctahedra that share corners with four equivalent PbIr12 cuboctahedra, corners with eight equivalent IrIr8Pb4 cuboctahedra, edges with eight equivalent PbIr12 cuboctahedra, edges with sixteen equivalent IrIr8Pb4 cuboctahedra, faces with four equivalent PbIr12 cuboctahedra, and faces with fourteen IrIr8Pb4 cuboctahedra.