YbPrCo17 crystallizes in the hexagonal P6_3/mmc space group. Yb(1) is bonded in a 18-coordinate geometry to six equivalent Co(4) and twelve equivalent Co(2) atoms. Pr(1) is bonded in a 20-coordinate geometry to two equivalent Co(1), six equivalent Co(2), six equivalent Co(3), and six equivalent Co(4) atoms. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to one Pr(1), one Co(1), three equivalent Co(2), three equivalent Co(3), and six equivalent Co(4) atoms. In the second Co site, Co(2) is bonded to two equivalent Yb(1), one Pr(1), one Co(1), two equivalent Co(2), two equivalent Co(3), and four equivalent Co(4) atoms to form distorted CoYb2PrCo9 cuboctahedra that share corners with five equivalent Co(3)Pr2Co10 cuboctahedra, corners with eight equivalent Co(4)YbPrCo10 cuboctahedra, corners with ten equivalent Co(2)Yb2PrCo9 cuboctahedra, edges with two equivalent Co(4)YbPrCo10 cuboctahedra, edges with three equivalent Co(3)Pr2Co10 cuboctahedra, edges with five equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with two equivalent Co(3)Pr2Co10 cuboctahedra, faces with eight equivalent Co(2)Yb2PrCo9 cuboctahedra, and faces with ten equivalent Co(4)YbPrCo10 cuboctahedra. In the third Co site, Co(3) is bonded to two equivalent Pr(1), two equivalent Co(1), four equivalent Co(2), and four equivalent Co(4) atoms to form CoPr2Co10 cuboctahedra that share corners with four equivalent Co(3)Pr2Co10 cuboctahedra, corners with eight equivalent Co(4)YbPrCo10 cuboctahedra, corners with ten equivalent Co(2)Yb2PrCo9 cuboctahedra, edges with four equivalent Co(4)YbPrCo10 cuboctahedra, edges with six equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with four equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with six equivalent Co(3)Pr2Co10 cuboctahedra, and faces with eight equivalent Co(4)YbPrCo10 cuboctahedra. In the fourth Co site, Co(4) is bonded to one Yb(1), one Pr(1), two equivalent Co(1), two equivalent Co(3), two equivalent Co(4), and four equivalent Co(2) atoms to form distorted CoYbPrCo10 cuboctahedra that share corners with four equivalent Co(3)Pr2Co10 cuboctahedra, corners with eight equivalent Co(2)Yb2PrCo9 cuboctahedra, corners with twelve equivalent Co(4)YbPrCo10 cuboctahedra,  an edgeedge with one Co(4)YbPrCo10 cuboctahedra, edges with two equivalent Co(3)Pr2Co10 cuboctahedra, edges with two equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with four equivalent Co(3)Pr2Co10 cuboctahedra, faces with seven equivalent Co(4)YbPrCo10 cuboctahedra, and faces with ten equivalent Co(2)Yb2PrCo9 cuboctahedra.
YbPrCo17 crystallizes in the hexagonal P6_3/mmc space group. Yb(1) is bonded in a 18-coordinate geometry to six equivalent Co(4) and twelve equivalent Co(2) atoms. All Yb(1)-Co(4) bond lengths are 2.97 Å. There are six shorter (3.05 Å) and six longer (3.24 Å) Yb(1)-Co(2) bond lengths. Pr(1) is bonded in a 20-coordinate geometry to two equivalent Co(1), six equivalent Co(2), six equivalent Co(3), and six equivalent Co(4) atoms. Both Pr(1)-Co(1) bond lengths are 2.93 Å. All Pr(1)-Co(2) bond lengths are 3.08 Å. All Pr(1)-Co(3) bond lengths are 3.16 Å. All Pr(1)-Co(4) bond lengths are 3.02 Å. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded in a 14-coordinate geometry to one Pr(1), one Co(1), three equivalent Co(2), three equivalent Co(3), and six equivalent Co(4) atoms. The Co(1)-Co(1) bond length is 2.32 Å. All Co(1)-Co(2) bond lengths are 2.63 Å. All Co(1)-Co(3) bond lengths are 2.56 Å. All Co(1)-Co(4) bond lengths are 2.65 Å. In the second Co site, Co(2) is bonded to two equivalent Yb(1), one Pr(1), one Co(1), two equivalent Co(2), two equivalent Co(3), and four equivalent Co(4) atoms to form distorted CoYb2PrCo9 cuboctahedra that share corners with five equivalent Co(3)Pr2Co10 cuboctahedra, corners with eight equivalent Co(4)YbPrCo10 cuboctahedra, corners with ten equivalent Co(2)Yb2PrCo9 cuboctahedra, edges with two equivalent Co(4)YbPrCo10 cuboctahedra, edges with three equivalent Co(3)Pr2Co10 cuboctahedra, edges with five equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with two equivalent Co(3)Pr2Co10 cuboctahedra, faces with eight equivalent Co(2)Yb2PrCo9 cuboctahedra, and faces with ten equivalent Co(4)YbPrCo10 cuboctahedra. Both Co(2)-Co(2) bond lengths are 2.40 Å. Both Co(2)-Co(3) bond lengths are 2.42 Å. There are two shorter (2.50 Å) and two longer (2.60 Å) Co(2)-Co(4) bond lengths. In the third Co site, Co(3) is bonded to two equivalent Pr(1), two equivalent Co(1), four equivalent Co(2), and four equivalent Co(4) atoms to form CoPr2Co10 cuboctahedra that share corners with four equivalent Co(3)Pr2Co10 cuboctahedra, corners with eight equivalent Co(4)YbPrCo10 cuboctahedra, corners with ten equivalent Co(2)Yb2PrCo9 cuboctahedra, edges with four equivalent Co(4)YbPrCo10 cuboctahedra, edges with six equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with four equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with six equivalent Co(3)Pr2Co10 cuboctahedra, and faces with eight equivalent Co(4)YbPrCo10 cuboctahedra. All Co(3)-Co(4) bond lengths are 2.41 Å. In the fourth Co site, Co(4) is bonded to one Yb(1), one Pr(1), two equivalent Co(1), two equivalent Co(3), two equivalent Co(4), and four equivalent Co(2) atoms to form distorted CoYbPrCo10 cuboctahedra that share corners with four equivalent Co(3)Pr2Co10 cuboctahedra, corners with eight equivalent Co(2)Yb2PrCo9 cuboctahedra, corners with twelve equivalent Co(4)YbPrCo10 cuboctahedra,  an edgeedge with one Co(4)YbPrCo10 cuboctahedra, edges with two equivalent Co(3)Pr2Co10 cuboctahedra, edges with two equivalent Co(2)Yb2PrCo9 cuboctahedra, faces with four equivalent Co(3)Pr2Co10 cuboctahedra, faces with seven equivalent Co(4)YbPrCo10 cuboctahedra, and faces with ten equivalent Co(2)Yb2PrCo9 cuboctahedra. There is one shorter (2.33 Å) and one longer (2.45 Å) Co(4)-Co(4) bond length.