Be17Sc2 crystallizes in the hexagonal P6_3/mmc space group. There are four inequivalent Be sites. In the first Be site, Be(4) is bonded to two equivalent Be(2), four equivalent Be(1), four equivalent Be(3), and two equivalent Sc(2) atoms to form distorted BeSc2Be10 cuboctahedra that share corners with four equivalent Be(4)Sc2Be10 cuboctahedra, corners with eight equivalent Be(3)Sc2Be10 cuboctahedra, corners with ten equivalent Be(1)Sc3Be9 cuboctahedra, edges with four equivalent Be(3)Sc2Be10 cuboctahedra, edges with six equivalent Be(1)Sc3Be9 cuboctahedra, faces with four equivalent Be(1)Sc3Be9 cuboctahedra, faces with six equivalent Be(4)Sc2Be10 cuboctahedra, and faces with eight equivalent Be(3)Sc2Be10 cuboctahedra. In the second Be site, Be(1) is bonded to one Be(2), two equivalent Be(1), two equivalent Be(4), four equivalent Be(3), one Sc(2), and two equivalent Sc(1) atoms to form distorted BeSc3Be9 cuboctahedra that share corners with five equivalent Be(4)Sc2Be10 cuboctahedra, corners with eight equivalent Be(3)Sc2Be10 cuboctahedra, corners with ten equivalent Be(1)Sc3Be9 cuboctahedra, edges with two equivalent Be(3)Sc2Be10 cuboctahedra, edges with three equivalent Be(4)Sc2Be10 cuboctahedra, edges with five equivalent Be(1)Sc3Be9 cuboctahedra, faces with two equivalent Be(4)Sc2Be10 cuboctahedra, faces with eight equivalent Be(1)Sc3Be9 cuboctahedra, and faces with ten equivalent Be(3)Sc2Be10 cuboctahedra. In the third Be site, Be(2) is bonded in a 14-coordinate geometry to one Be(2), three equivalent Be(1), three equivalent Be(4), six equivalent Be(3), and one Sc(2) atom. In the fourth Be site, Be(3) is bonded to two equivalent Be(2), two equivalent Be(3), two equivalent Be(4), four equivalent Be(1), one Sc(1), and one Sc(2) atom to form distorted BeSc2Be10 cuboctahedra that share corners with four equivalent Be(4)Sc2Be10 cuboctahedra, corners with eight equivalent Be(1)Sc3Be9 cuboctahedra, corners with twelve equivalent Be(3)Sc2Be10 cuboctahedra,  an edgeedge with one Be(3)Sc2Be10 cuboctahedra, edges with two equivalent Be(4)Sc2Be10 cuboctahedra, edges with two equivalent Be(1)Sc3Be9 cuboctahedra, faces with four equivalent Be(4)Sc2Be10 cuboctahedra, faces with seven equivalent Be(3)Sc2Be10 cuboctahedra, and faces with ten equivalent Be(1)Sc3Be9 cuboctahedra. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 18-coordinate geometry to six equivalent Be(3) and twelve equivalent Be(1) atoms. In the second Sc site, Sc(2) is bonded in a 20-coordinate geometry to two equivalent Be(2), six equivalent Be(1), six equivalent Be(3), and six equivalent Be(4) atoms.
Be17Sc2 crystallizes in the hexagonal P6_3/mmc space group. There are four inequivalent Be sites. In the first Be site, Be(4) is bonded to two equivalent Be(2), four equivalent Be(1), four equivalent Be(3), and two equivalent Sc(2) atoms to form distorted BeSc2Be10 cuboctahedra that share corners with four equivalent Be(4)Sc2Be10 cuboctahedra, corners with eight equivalent Be(3)Sc2Be10 cuboctahedra, corners with ten equivalent Be(1)Sc3Be9 cuboctahedra, edges with four equivalent Be(3)Sc2Be10 cuboctahedra, edges with six equivalent Be(1)Sc3Be9 cuboctahedra, faces with four equivalent Be(1)Sc3Be9 cuboctahedra, faces with six equivalent Be(4)Sc2Be10 cuboctahedra, and faces with eight equivalent Be(3)Sc2Be10 cuboctahedra. Both Be(4)-Be(2) bond lengths are 2.31 Å. All Be(4)-Be(1) bond lengths are 2.18 Å. All Be(4)-Be(3) bond lengths are 2.16 Å. Both Be(4)-Sc(2) bond lengths are 2.84 Å. In the second Be site, Be(1) is bonded to one Be(2), two equivalent Be(1), two equivalent Be(4), four equivalent Be(3), one Sc(2), and two equivalent Sc(1) atoms to form distorted BeSc3Be9 cuboctahedra that share corners with five equivalent Be(4)Sc2Be10 cuboctahedra, corners with eight equivalent Be(3)Sc2Be10 cuboctahedra, corners with ten equivalent Be(1)Sc3Be9 cuboctahedra, edges with two equivalent Be(3)Sc2Be10 cuboctahedra, edges with three equivalent Be(4)Sc2Be10 cuboctahedra, edges with five equivalent Be(1)Sc3Be9 cuboctahedra, faces with two equivalent Be(4)Sc2Be10 cuboctahedra, faces with eight equivalent Be(1)Sc3Be9 cuboctahedra, and faces with ten equivalent Be(3)Sc2Be10 cuboctahedra. The Be(1)-Be(2) bond length is 2.35 Å. Both Be(1)-Be(1) bond lengths are 2.17 Å. There are two shorter (2.22 Å) and two longer (2.37 Å) Be(1)-Be(3) bond lengths. The Be(1)-Sc(2) bond length is 2.80 Å. There is one shorter (2.78 Å) and one longer (2.89 Å) Be(1)-Sc(1) bond length. In the third Be site, Be(2) is bonded in a 14-coordinate geometry to one Be(2), three equivalent Be(1), three equivalent Be(4), six equivalent Be(3), and one Sc(2) atom. The Be(2)-Be(2) bond length is 2.12 Å. All Be(2)-Be(3) bond lengths are 2.41 Å. The Be(2)-Sc(2) bond length is 2.61 Å. In the fourth Be site, Be(3) is bonded to two equivalent Be(2), two equivalent Be(3), two equivalent Be(4), four equivalent Be(1), one Sc(1), and one Sc(2) atom to form distorted BeSc2Be10 cuboctahedra that share corners with four equivalent Be(4)Sc2Be10 cuboctahedra, corners with eight equivalent Be(1)Sc3Be9 cuboctahedra, corners with twelve equivalent Be(3)Sc2Be10 cuboctahedra,  an edgeedge with one Be(3)Sc2Be10 cuboctahedra, edges with two equivalent Be(4)Sc2Be10 cuboctahedra, edges with two equivalent Be(1)Sc3Be9 cuboctahedra, faces with four equivalent Be(4)Sc2Be10 cuboctahedra, faces with seven equivalent Be(3)Sc2Be10 cuboctahedra, and faces with ten equivalent Be(1)Sc3Be9 cuboctahedra. There is one shorter (2.15 Å) and one longer (2.19 Å) Be(3)-Be(3) bond length. The Be(3)-Sc(1) bond length is 2.69 Å. The Be(3)-Sc(2) bond length is 2.71 Å. There are two inequivalent Sc sites. In the first Sc site, Sc(1) is bonded in a 18-coordinate geometry to six equivalent Be(3) and twelve equivalent Be(1) atoms. In the second Sc site, Sc(2) is bonded in a 20-coordinate geometry to two equivalent Be(2), six equivalent Be(1), six equivalent Be(3), and six equivalent Be(4) atoms.