Sm2Zn17 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 18-coordinate geometry to six equivalent Zn(3) and twelve equivalent Zn(4) atoms. In the second Sm site, Sm(2) is bonded in a 20-coordinate geometry to two equivalent Zn(1), six equivalent Zn(2), six equivalent Zn(3), and six equivalent Zn(4) atoms. There are four inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 14-coordinate geometry to one Sm(2), one Zn(1), three equivalent Zn(2), three equivalent Zn(4), and six equivalent Zn(3) atoms. In the second Zn site, Zn(2) is bonded to two equivalent Sm(2), two equivalent Zn(1), four equivalent Zn(3), and four equivalent Zn(4) atoms to form ZnSm2Zn10 cuboctahedra that share corners with four equivalent Zn(2)Sm2Zn10 cuboctahedra, corners with eight equivalent Zn(3)Sm2Zn10 cuboctahedra, corners with ten equivalent Zn(4)Sm3Zn9 cuboctahedra, edges with four equivalent Zn(3)Sm2Zn10 cuboctahedra, edges with six equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with four equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with six equivalent Zn(2)Sm2Zn10 cuboctahedra, and faces with eight equivalent Zn(3)Sm2Zn10 cuboctahedra. In the third Zn site, Zn(3) is bonded to one Sm(1), one Sm(2), two equivalent Zn(1), two equivalent Zn(2), two equivalent Zn(3), and four equivalent Zn(4) atoms to form distorted ZnSm2Zn10 cuboctahedra that share corners with four equivalent Zn(2)Sm2Zn10 cuboctahedra, corners with eight equivalent Zn(4)Sm3Zn9 cuboctahedra, corners with twelve equivalent Zn(3)Sm2Zn10 cuboctahedra,  an edgeedge with one Zn(3)Sm2Zn10 cuboctahedra, edges with two equivalent Zn(2)Sm2Zn10 cuboctahedra, edges with two equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with four equivalent Zn(2)Sm2Zn10 cuboctahedra, faces with seven equivalent Zn(3)Sm2Zn10 cuboctahedra, and faces with ten equivalent Zn(4)Sm3Zn9 cuboctahedra. In the fourth Zn site, Zn(4) is bonded to one Sm(2), two equivalent Sm(1), one Zn(1), two equivalent Zn(2), two equivalent Zn(4), and four equivalent Zn(3) atoms to form distorted ZnSm3Zn9 cuboctahedra that share corners with five equivalent Zn(2)Sm2Zn10 cuboctahedra, corners with eight equivalent Zn(3)Sm2Zn10 cuboctahedra, corners with ten equivalent Zn(4)Sm3Zn9 cuboctahedra, edges with two equivalent Zn(3)Sm2Zn10 cuboctahedra, edges with three equivalent Zn(2)Sm2Zn10 cuboctahedra, edges with five equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with two equivalent Zn(2)Sm2Zn10 cuboctahedra, faces with eight equivalent Zn(4)Sm3Zn9 cuboctahedra, and faces with ten equivalent Zn(3)Sm2Zn10 cuboctahedra.
Sm2Zn17 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 18-coordinate geometry to six equivalent Zn(3) and twelve equivalent Zn(4) atoms. All Sm(1)-Zn(3) bond lengths are 3.15 Å. There are six shorter (3.24 Å) and six longer (3.45 Å) Sm(1)-Zn(4) bond lengths. In the second Sm site, Sm(2) is bonded in a 20-coordinate geometry to two equivalent Zn(1), six equivalent Zn(2), six equivalent Zn(3), and six equivalent Zn(4) atoms. Both Sm(2)-Zn(1) bond lengths are 3.04 Å. All Sm(2)-Zn(2) bond lengths are 3.40 Å. All Sm(2)-Zn(3) bond lengths are 3.21 Å. All Sm(2)-Zn(4) bond lengths are 3.36 Å. There are four inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 14-coordinate geometry to one Sm(2), one Zn(1), three equivalent Zn(2), three equivalent Zn(4), and six equivalent Zn(3) atoms. The Zn(1)-Zn(1) bond length is 2.64 Å. All Zn(1)-Zn(2) bond lengths are 2.75 Å. All Zn(1)-Zn(4) bond lengths are 2.88 Å. All Zn(1)-Zn(3) bond lengths are 3.01 Å. In the second Zn site, Zn(2) is bonded to two equivalent Sm(2), two equivalent Zn(1), four equivalent Zn(3), and four equivalent Zn(4) atoms to form ZnSm2Zn10 cuboctahedra that share corners with four equivalent Zn(2)Sm2Zn10 cuboctahedra, corners with eight equivalent Zn(3)Sm2Zn10 cuboctahedra, corners with ten equivalent Zn(4)Sm3Zn9 cuboctahedra, edges with four equivalent Zn(3)Sm2Zn10 cuboctahedra, edges with six equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with four equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with six equivalent Zn(2)Sm2Zn10 cuboctahedra, and faces with eight equivalent Zn(3)Sm2Zn10 cuboctahedra. All Zn(2)-Zn(3) bond lengths are 2.60 Å. All Zn(2)-Zn(4) bond lengths are 2.66 Å. In the third Zn site, Zn(3) is bonded to one Sm(1), one Sm(2), two equivalent Zn(1), two equivalent Zn(2), two equivalent Zn(3), and four equivalent Zn(4) atoms to form distorted ZnSm2Zn10 cuboctahedra that share corners with four equivalent Zn(2)Sm2Zn10 cuboctahedra, corners with eight equivalent Zn(4)Sm3Zn9 cuboctahedra, corners with twelve equivalent Zn(3)Sm2Zn10 cuboctahedra,  an edgeedge with one Zn(3)Sm2Zn10 cuboctahedra, edges with two equivalent Zn(2)Sm2Zn10 cuboctahedra, edges with two equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with four equivalent Zn(2)Sm2Zn10 cuboctahedra, faces with seven equivalent Zn(3)Sm2Zn10 cuboctahedra, and faces with ten equivalent Zn(4)Sm3Zn9 cuboctahedra. There is one shorter (2.64 Å) and one longer (2.76 Å) Zn(3)-Zn(3) bond length. There are two shorter (2.71 Å) and two longer (2.72 Å) Zn(3)-Zn(4) bond lengths. In the fourth Zn site, Zn(4) is bonded to one Sm(2), two equivalent Sm(1), one Zn(1), two equivalent Zn(2), two equivalent Zn(4), and four equivalent Zn(3) atoms to form distorted ZnSm3Zn9 cuboctahedra that share corners with five equivalent Zn(2)Sm2Zn10 cuboctahedra, corners with eight equivalent Zn(3)Sm2Zn10 cuboctahedra, corners with ten equivalent Zn(4)Sm3Zn9 cuboctahedra, edges with two equivalent Zn(3)Sm2Zn10 cuboctahedra, edges with three equivalent Zn(2)Sm2Zn10 cuboctahedra, edges with five equivalent Zn(4)Sm3Zn9 cuboctahedra, faces with two equivalent Zn(2)Sm2Zn10 cuboctahedra, faces with eight equivalent Zn(4)Sm3Zn9 cuboctahedra, and faces with ten equivalent Zn(3)Sm2Zn10 cuboctahedra. Both Zn(4)-Zn(4) bond lengths are 2.55 Å.