Y8Co5 crystallizes in the monoclinic P2_1/c space group. There are eight inequivalent Y sites. In the first Y site, Y(1) is bonded in a 4-coordinate geometry to one Co(1), one Co(2), and two equivalent Co(5) atoms. In the second Y site, Y(2) is bonded in a 5-coordinate geometry to one Co(2), one Co(4), one Co(5), and two equivalent Co(3) atoms. In the third Y site, Y(3) is bonded in a 6-coordinate geometry to one Co(2), one Co(5), two equivalent Co(3), and two equivalent Co(4) atoms. In the fourth Y site, Y(4) is bonded in a 4-coordinate geometry to one Co(2), one Co(5), and two equivalent Co(1) atoms. In the fifth Y site, Y(5) is bonded in a 4-coordinate geometry to one Co(1), one Co(2), one Co(3), and two equivalent Co(4) atoms. In the sixth Y site, Y(6) is bonded in a 4-coordinate geometry to one Co(2), two equivalent Co(3), and two equivalent Co(4) atoms. In the seventh Y site, Y(7) is bonded in a 4-coordinate geometry to one Co(3), one Co(5), and two equivalent Co(1) atoms. In the eighth Y site, Y(8) is bonded in a 3-coordinate geometry to one Co(2), one Co(5), and two equivalent Co(1) atoms. There are five inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Y(1), one Y(5), two equivalent Y(4), two equivalent Y(7), two equivalent Y(8), and one Co(1) atom. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(6), one Y(8), one Co(4), and one Co(5) atom. In the third Co site, Co(3) is bonded in a 9-coordinate geometry to one Y(5), one Y(7), two equivalent Y(2), two equivalent Y(3), two equivalent Y(6), and one Co(4) atom. In the fourth Co site, Co(4) is bonded in a 9-coordinate geometry to one Y(2), two equivalent Y(3), two equivalent Y(5), two equivalent Y(6), one Co(2), and one Co(3) atom. In the fifth Co site, Co(5) is bonded in a 8-coordinate geometry to one Y(2), one Y(3), one Y(4), one Y(7), one Y(8), two equivalent Y(1), and one Co(2) atom.
Y8Co5 crystallizes in the monoclinic P2_1/c space group. There are eight inequivalent Y sites. In the first Y site, Y(1) is bonded in a 4-coordinate geometry to one Co(1), one Co(2), and two equivalent Co(5) atoms. The Y(1)-Co(1) bond length is 2.76 Å. The Y(1)-Co(2) bond length is 2.85 Å. There is one shorter (2.85 Å) and one longer (3.19 Å) Y(1)-Co(5) bond length. In the second Y site, Y(2) is bonded in a 5-coordinate geometry to one Co(2), one Co(4), one Co(5), and two equivalent Co(3) atoms. The Y(2)-Co(2) bond length is 2.96 Å. The Y(2)-Co(4) bond length is 2.89 Å. The Y(2)-Co(5) bond length is 2.82 Å. There is one shorter (2.76 Å) and one longer (2.86 Å) Y(2)-Co(3) bond length. In the third Y site, Y(3) is bonded in a 6-coordinate geometry to one Co(2), one Co(5), two equivalent Co(3), and two equivalent Co(4) atoms. The Y(3)-Co(2) bond length is 2.96 Å. The Y(3)-Co(5) bond length is 2.98 Å. There is one shorter (2.87 Å) and one longer (2.88 Å) Y(3)-Co(3) bond length. There is one shorter (2.92 Å) and one longer (3.15 Å) Y(3)-Co(4) bond length. In the fourth Y site, Y(4) is bonded in a 4-coordinate geometry to one Co(2), one Co(5), and two equivalent Co(1) atoms. The Y(4)-Co(2) bond length is 2.78 Å. The Y(4)-Co(5) bond length is 2.79 Å. There is one shorter (2.74 Å) and one longer (2.89 Å) Y(4)-Co(1) bond length. In the fifth Y site, Y(5) is bonded in a 4-coordinate geometry to one Co(1), one Co(2), one Co(3), and two equivalent Co(4) atoms. The Y(5)-Co(1) bond length is 3.56 Å. The Y(5)-Co(2) bond length is 2.80 Å. The Y(5)-Co(3) bond length is 2.81 Å. Both Y(5)-Co(4) bond lengths are 2.82 Å. In the sixth Y site, Y(6) is bonded in a 4-coordinate geometry to one Co(2), two equivalent Co(3), and two equivalent Co(4) atoms. The Y(6)-Co(2) bond length is 2.84 Å. There is one shorter (2.76 Å) and one longer (3.62 Å) Y(6)-Co(3) bond length. Both Y(6)-Co(4) bond lengths are 2.79 Å. In the seventh Y site, Y(7) is bonded in a 4-coordinate geometry to one Co(3), one Co(5), and two equivalent Co(1) atoms. The Y(7)-Co(3) bond length is 3.20 Å. The Y(7)-Co(5) bond length is 2.80 Å. There is one shorter (2.93 Å) and one longer (2.94 Å) Y(7)-Co(1) bond length. In the eighth Y site, Y(8) is bonded in a 3-coordinate geometry to one Co(2), one Co(5), and two equivalent Co(1) atoms. The Y(8)-Co(2) bond length is 3.00 Å. The Y(8)-Co(5) bond length is 2.74 Å. There is one shorter (2.79 Å) and one longer (3.34 Å) Y(8)-Co(1) bond length. There are five inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Y(1), one Y(5), two equivalent Y(4), two equivalent Y(7), two equivalent Y(8), and one Co(1) atom. The Co(1)-Co(1) bond length is 2.31 Å. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Y(1), one Y(2), one Y(3), one Y(4), one Y(5), one Y(6), one Y(8), one Co(4), and one Co(5) atom. The Co(2)-Co(4) bond length is 2.45 Å. The Co(2)-Co(5) bond length is 2.34 Å. In the third Co site, Co(3) is bonded in a 9-coordinate geometry to one Y(5), one Y(7), two equivalent Y(2), two equivalent Y(3), two equivalent Y(6), and one Co(4) atom. The Co(3)-Co(4) bond length is 2.43 Å. In the fourth Co site, Co(4) is bonded in a 9-coordinate geometry to one Y(2), two equivalent Y(3), two equivalent Y(5), two equivalent Y(6), one Co(2), and one Co(3) atom. In the fifth Co site, Co(5) is bonded in a 8-coordinate geometry to one Y(2), one Y(3), one Y(4), one Y(7), one Y(8), two equivalent Y(1), and one Co(2) atom.