Y2Co14Cu3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 18-coordinate geometry to six equivalent Co(2) and twelve equivalent Co(3) atoms. In the second Y site, Y(2) is bonded in a 20-coordinate geometry to two equivalent Co(1), six equivalent Co(2), six equivalent Co(3), and six equivalent Cu(1) atoms. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to one Y(2), one Co(1), three equivalent Co(3), six equivalent Co(2), and three equivalent Cu(1) atoms. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to one Y(1), one Y(2), two equivalent Co(1), two equivalent Co(2), four equivalent Co(3), and two equivalent Cu(1) atoms. In the third Co site, Co(3) is bonded to one Y(2), two equivalent Y(1), one Co(1), two equivalent Co(3), four equivalent Co(2), and two equivalent Cu(1) atoms to form distorted CoY3Co7Cu2 cuboctahedra that share corners with five equivalent Cu(1)Y2Co10 cuboctahedra, corners with ten equivalent Co(3)Y3Co7Cu2 cuboctahedra, edges with three equivalent Cu(1)Y2Co10 cuboctahedra, edges with five equivalent Co(3)Y3Co7Cu2 cuboctahedra, faces with two equivalent Cu(1)Y2Co10 cuboctahedra, and faces with eight equivalent Co(3)Y3Co7Cu2 cuboctahedra. Cu(1) is bonded to two equivalent Y(2), two equivalent Co(1), four equivalent Co(2), and four equivalent Co(3) atoms to form CuY2Co10 cuboctahedra that share corners with four equivalent Cu(1)Y2Co10 cuboctahedra, corners with ten equivalent Co(3)Y3Co7Cu2 cuboctahedra, edges with six equivalent Co(3)Y3Co7Cu2 cuboctahedra, faces with four equivalent Co(3)Y3Co7Cu2 cuboctahedra, and faces with six equivalent Cu(1)Y2Co10 cuboctahedra.
Y2Co14Cu3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 18-coordinate geometry to six equivalent Co(2) and twelve equivalent Co(3) atoms. All Y(1)-Co(2) bond lengths are 2.94 Å. There are six shorter (3.02 Å) and six longer (3.17 Å) Y(1)-Co(3) bond lengths. In the second Y site, Y(2) is bonded in a 20-coordinate geometry to two equivalent Co(1), six equivalent Co(2), six equivalent Co(3), and six equivalent Cu(1) atoms. Both Y(2)-Co(1) bond lengths are 2.94 Å. All Y(2)-Co(2) bond lengths are 3.01 Å. All Y(2)-Co(3) bond lengths are 3.13 Å. All Y(2)-Cu(1) bond lengths are 3.15 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to one Y(2), one Co(1), three equivalent Co(3), six equivalent Co(2), and three equivalent Cu(1) atoms. The Co(1)-Co(1) bond length is 2.27 Å. All Co(1)-Co(3) bond lengths are 2.68 Å. All Co(1)-Co(2) bond lengths are 2.66 Å. All Co(1)-Cu(1) bond lengths are 2.56 Å. In the second Co site, Co(2) is bonded in a 12-coordinate geometry to one Y(1), one Y(2), two equivalent Co(1), two equivalent Co(2), four equivalent Co(3), and two equivalent Cu(1) atoms. There is one shorter (2.33 Å) and one longer (2.48 Å) Co(2)-Co(2) bond length. There are two shorter (2.48 Å) and two longer (2.60 Å) Co(2)-Co(3) bond lengths. Both Co(2)-Cu(1) bond lengths are 2.41 Å. In the third Co site, Co(3) is bonded to one Y(2), two equivalent Y(1), one Co(1), two equivalent Co(3), four equivalent Co(2), and two equivalent Cu(1) atoms to form distorted CoY3Co7Cu2 cuboctahedra that share corners with five equivalent Cu(1)Y2Co10 cuboctahedra, corners with ten equivalent Co(3)Y3Co7Cu2 cuboctahedra, edges with three equivalent Cu(1)Y2Co10 cuboctahedra, edges with five equivalent Co(3)Y3Co7Cu2 cuboctahedra, faces with two equivalent Cu(1)Y2Co10 cuboctahedra, and faces with eight equivalent Co(3)Y3Co7Cu2 cuboctahedra. Both Co(3)-Co(3) bond lengths are 2.34 Å. Both Co(3)-Cu(1) bond lengths are 2.44 Å. Cu(1) is bonded to two equivalent Y(2), two equivalent Co(1), four equivalent Co(2), and four equivalent Co(3) atoms to form CuY2Co10 cuboctahedra that share corners with four equivalent Cu(1)Y2Co10 cuboctahedra, corners with ten equivalent Co(3)Y3Co7Cu2 cuboctahedra, edges with six equivalent Co(3)Y3Co7Cu2 cuboctahedra, faces with four equivalent Co(3)Y3Co7Cu2 cuboctahedra, and faces with six equivalent Cu(1)Y2Co10 cuboctahedra.