Y2(NiCu)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 18-coordinate geometry to four equivalent Ni(1), eight equivalent Ni(2), two equivalent Cu(1), and four equivalent Cu(2) atoms. In the second Y site, Y(2) is bonded in a 18-coordinate geometry to eight equivalent Ni(2), two equivalent Cu(2), four equivalent Cu(1), and four equivalent Cu(3) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Y(1), four equivalent Ni(2), and four equivalent Cu(2) atoms to form NiY4Cu4Ni4 cuboctahedra that share corners with four equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, corners with four equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, edges with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, faces with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Y(1), two equivalent Y(2), one Ni(1), two equivalent Ni(2), one Cu(3), two equivalent Cu(1), and two equivalent Cu(2) atoms to form NiY4Cu5Ni3 cuboctahedra that share corners with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, corners with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, corners with twelve equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, edges with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, edges with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, edges with six equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, faces with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, faces with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, and faces with six equivalent Ni(2)Y4Cu5Ni3 cuboctahedra. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 9-coordinate geometry to one Y(1), two equivalent Y(2), four equivalent Ni(2), and two equivalent Cu(3) atoms. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to one Y(2), two equivalent Y(1), two equivalent Ni(1), and four equivalent Ni(2) atoms. In the third Cu site, Cu(3) is bonded to four equivalent Y(2), four equivalent Ni(2), and four equivalent Cu(1) atoms to form CuY4Cu4Ni4 cuboctahedra that share corners with four equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, corners with four equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, edges with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, faces with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra.
Y2(NiCu)5 crystallizes in the orthorhombic Pmmm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 18-coordinate geometry to four equivalent Ni(1), eight equivalent Ni(2), two equivalent Cu(1), and four equivalent Cu(2) atoms. All Y(1)-Ni(1) bond lengths are 3.16 Å. All Y(1)-Ni(2) bond lengths are 3.14 Å. Both Y(1)-Cu(1) bond lengths are 2.81 Å. All Y(1)-Cu(2) bond lengths are 2.86 Å. In the second Y site, Y(2) is bonded in a 18-coordinate geometry to eight equivalent Ni(2), two equivalent Cu(2), four equivalent Cu(1), and four equivalent Cu(3) atoms. All Y(2)-Ni(2) bond lengths are 3.15 Å. Both Y(2)-Cu(2) bond lengths are 2.83 Å. All Y(2)-Cu(1) bond lengths are 2.87 Å. All Y(2)-Cu(3) bond lengths are 3.16 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to four equivalent Y(1), four equivalent Ni(2), and four equivalent Cu(2) atoms to form NiY4Cu4Ni4 cuboctahedra that share corners with four equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, corners with four equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, edges with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, faces with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra. All Ni(1)-Ni(2) bond lengths are 2.45 Å. All Ni(1)-Cu(2) bond lengths are 2.43 Å. In the second Ni site, Ni(2) is bonded to two equivalent Y(1), two equivalent Y(2), one Ni(1), two equivalent Ni(2), one Cu(3), two equivalent Cu(1), and two equivalent Cu(2) atoms to form NiY4Cu5Ni3 cuboctahedra that share corners with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, corners with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, corners with twelve equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, edges with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, edges with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, edges with six equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, faces with two equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, faces with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, and faces with six equivalent Ni(2)Y4Cu5Ni3 cuboctahedra. There is one shorter (2.46 Å) and one longer (2.48 Å) Ni(2)-Ni(2) bond length. The Ni(2)-Cu(3) bond length is 2.47 Å. Both Ni(2)-Cu(1) bond lengths are 2.42 Å. Both Ni(2)-Cu(2) bond lengths are 2.42 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 9-coordinate geometry to one Y(1), two equivalent Y(2), four equivalent Ni(2), and two equivalent Cu(3) atoms. Both Cu(1)-Cu(3) bond lengths are 2.44 Å. In the second Cu site, Cu(2) is bonded in a 9-coordinate geometry to one Y(2), two equivalent Y(1), two equivalent Ni(1), and four equivalent Ni(2) atoms. In the third Cu site, Cu(3) is bonded to four equivalent Y(2), four equivalent Ni(2), and four equivalent Cu(1) atoms to form CuY4Cu4Ni4 cuboctahedra that share corners with four equivalent Ni(1)Y4Cu4Ni4 cuboctahedra, corners with four equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, corners with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, edges with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, edges with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra, faces with two equivalent Cu(3)Y4Cu4Ni4 cuboctahedra, and faces with eight equivalent Ni(2)Y4Cu5Ni3 cuboctahedra.