Y5CuPb3 crystallizes in the hexagonal P6_3/mcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to two equivalent Cu(1) and five equivalent Pb(1) atoms. In the second Y site, Y(2) is bonded to six equivalent Pb(1) atoms to form a mixture of distorted edge, corner, and face-sharing YPb6 octahedra. The corner-sharing octahedral tilt angles are 35°. Cu(1) is bonded to six equivalent Y(1) atoms to form face-sharing CuY6 octahedra. Pb(1) is bonded in a 9-coordinate geometry to four equivalent Y(2) and five equivalent Y(1) atoms.
Y5CuPb3 crystallizes in the hexagonal P6_3/mcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to two equivalent Cu(1) and five equivalent Pb(1) atoms. Both Y(1)-Cu(1) bond lengths are 2.82 Å. There are a spread of Y(1)-Pb(1) bond distances ranging from 3.08-3.61 Å. In the second Y site, Y(2) is bonded to six equivalent Pb(1) atoms to form a mixture of distorted edge, corner, and face-sharing YPb6 octahedra. The corner-sharing octahedral tilt angles are 35°. All Y(2)-Pb(1) bond lengths are 3.24 Å. Cu(1) is bonded to six equivalent Y(1) atoms to form face-sharing CuY6 octahedra. Pb(1) is bonded in a 9-coordinate geometry to four equivalent Y(2) and five equivalent Y(1) atoms.