DySmFe17 crystallizes in the trigonal R3m space group. Dy(1) is bonded in a 19-coordinate geometry to one Fe(5), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and six equivalent Fe(4) atoms. Sm(1) is bonded in a 19-coordinate geometry to one Fe(6), three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(1), and six equivalent Fe(4) atoms. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Dy(1), two equivalent Sm(1), one Fe(6), two equivalent Fe(2), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeSm2DyFe9 cuboctahedra that share corners with two equivalent Fe(1)Sm2DyFe9 cuboctahedra, corners with five equivalent Fe(3)SmDyFe10 cuboctahedra, corners with eight equivalent Fe(2)SmDy2Fe9 cuboctahedra,  an edgeedge with one Fe(2)SmDy2Fe9 cuboctahedra, edges with three equivalent Fe(3)SmDyFe10 cuboctahedra, edges with four equivalent Fe(1)Sm2DyFe9 cuboctahedra, faces with three equivalent Fe(2)SmDy2Fe9 cuboctahedra, faces with three equivalent Fe(3)SmDyFe10 cuboctahedra, and faces with four equivalent Fe(1)Sm2DyFe9 cuboctahedra. In the second Fe site, Fe(2) is bonded to two equivalent Dy(1), one Sm(1), one Fe(5), two equivalent Fe(1), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeSmDy2Fe9 cuboctahedra that share corners with two equivalent Fe(2)SmDy2Fe9 cuboctahedra, corners with five equivalent Fe(3)SmDyFe10 cuboctahedra, corners with eight equivalent Fe(1)Sm2DyFe9 cuboctahedra,  an edgeedge with one Fe(1)Sm2DyFe9 cuboctahedra, edges with three equivalent Fe(3)SmDyFe10 cuboctahedra, edges with four equivalent Fe(2)SmDy2Fe9 cuboctahedra, faces with three equivalent Fe(1)Sm2DyFe9 cuboctahedra, faces with three equivalent Fe(3)SmDyFe10 cuboctahedra, and faces with four equivalent Fe(2)SmDy2Fe9 cuboctahedra. In the third Fe site, Fe(3) is bonded to one Dy(1), one Sm(1), one Fe(5), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), and four equivalent Fe(4) atoms to form FeSmDyFe10 cuboctahedra that share corners with four equivalent Fe(3)SmDyFe10 cuboctahedra, corners with five equivalent Fe(1)Sm2DyFe9 cuboctahedra, corners with five equivalent Fe(2)SmDy2Fe9 cuboctahedra, edges with three equivalent Fe(1)Sm2DyFe9 cuboctahedra, edges with three equivalent Fe(2)SmDy2Fe9 cuboctahedra, faces with three equivalent Fe(1)Sm2DyFe9 cuboctahedra, faces with three equivalent Fe(2)SmDy2Fe9 cuboctahedra, and faces with four equivalent Fe(3)SmDyFe10 cuboctahedra. In the fourth Fe site, Fe(4) is bonded in a 12-coordinate geometry to one Dy(1), one Sm(1), one Fe(5), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent Fe(4) atoms. In the fifth Fe site, Fe(5) is bonded in a 14-coordinate geometry to one Dy(1), one Fe(6), three equivalent Fe(2), three equivalent Fe(3), and six equivalent Fe(4) atoms. In the sixth Fe site, Fe(6) is bonded in a 14-coordinate geometry to one Sm(1), one Fe(5), three equivalent Fe(1), three equivalent Fe(3), and six equivalent Fe(4) atoms.
DySmFe17 crystallizes in the trigonal R3m space group. Dy(1) is bonded in a 19-coordinate geometry to one Fe(5), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and six equivalent Fe(4) atoms. The Dy(1)-Fe(5) bond length is 3.03 Å. All Dy(1)-Fe(1) bond lengths are 3.06 Å. All Dy(1)-Fe(3) bond lengths are 3.27 Å. There are three shorter (3.18 Å) and three longer (3.23 Å) Dy(1)-Fe(2) bond lengths. All Dy(1)-Fe(4) bond lengths are 3.02 Å. Sm(1) is bonded in a 19-coordinate geometry to one Fe(6), three equivalent Fe(2), three equivalent Fe(3), six equivalent Fe(1), and six equivalent Fe(4) atoms. The Sm(1)-Fe(6) bond length is 3.04 Å. All Sm(1)-Fe(2) bond lengths are 3.06 Å. All Sm(1)-Fe(3) bond lengths are 3.28 Å. There are three shorter (3.19 Å) and three longer (3.23 Å) Sm(1)-Fe(1) bond lengths. All Sm(1)-Fe(4) bond lengths are 3.03 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Dy(1), two equivalent Sm(1), one Fe(6), two equivalent Fe(2), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeSm2DyFe9 cuboctahedra that share corners with two equivalent Fe(1)Sm2DyFe9 cuboctahedra, corners with five equivalent Fe(3)SmDyFe10 cuboctahedra, corners with eight equivalent Fe(2)SmDy2Fe9 cuboctahedra,  an edgeedge with one Fe(2)SmDy2Fe9 cuboctahedra, edges with three equivalent Fe(3)SmDyFe10 cuboctahedra, edges with four equivalent Fe(1)Sm2DyFe9 cuboctahedra, faces with three equivalent Fe(2)SmDy2Fe9 cuboctahedra, faces with three equivalent Fe(3)SmDyFe10 cuboctahedra, and faces with four equivalent Fe(1)Sm2DyFe9 cuboctahedra. The Fe(1)-Fe(6) bond length is 2.65 Å. Both Fe(1)-Fe(2) bond lengths are 2.47 Å. Both Fe(1)-Fe(3) bond lengths are 2.46 Å. There are two shorter (2.54 Å) and two longer (2.61 Å) Fe(1)-Fe(4) bond lengths. In the second Fe site, Fe(2) is bonded to two equivalent Dy(1), one Sm(1), one Fe(5), two equivalent Fe(1), two equivalent Fe(3), and four equivalent Fe(4) atoms to form FeSmDy2Fe9 cuboctahedra that share corners with two equivalent Fe(2)SmDy2Fe9 cuboctahedra, corners with five equivalent Fe(3)SmDyFe10 cuboctahedra, corners with eight equivalent Fe(1)Sm2DyFe9 cuboctahedra,  an edgeedge with one Fe(1)Sm2DyFe9 cuboctahedra, edges with three equivalent Fe(3)SmDyFe10 cuboctahedra, edges with four equivalent Fe(2)SmDy2Fe9 cuboctahedra, faces with three equivalent Fe(1)Sm2DyFe9 cuboctahedra, faces with three equivalent Fe(3)SmDyFe10 cuboctahedra, and faces with four equivalent Fe(2)SmDy2Fe9 cuboctahedra. The Fe(2)-Fe(5) bond length is 2.64 Å. Both Fe(2)-Fe(3) bond lengths are 2.45 Å. There are two shorter (2.54 Å) and two longer (2.62 Å) Fe(2)-Fe(4) bond lengths. In the third Fe site, Fe(3) is bonded to one Dy(1), one Sm(1), one Fe(5), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), and four equivalent Fe(4) atoms to form FeSmDyFe10 cuboctahedra that share corners with four equivalent Fe(3)SmDyFe10 cuboctahedra, corners with five equivalent Fe(1)Sm2DyFe9 cuboctahedra, corners with five equivalent Fe(2)SmDy2Fe9 cuboctahedra, edges with three equivalent Fe(1)Sm2DyFe9 cuboctahedra, edges with three equivalent Fe(2)SmDy2Fe9 cuboctahedra, faces with three equivalent Fe(1)Sm2DyFe9 cuboctahedra, faces with three equivalent Fe(2)SmDy2Fe9 cuboctahedra, and faces with four equivalent Fe(3)SmDyFe10 cuboctahedra. The Fe(3)-Fe(5) bond length is 2.60 Å. The Fe(3)-Fe(6) bond length is 2.61 Å. There are two shorter (2.42 Å) and two longer (2.43 Å) Fe(3)-Fe(4) bond lengths. In the fourth Fe site, Fe(4) is bonded in a 12-coordinate geometry to one Dy(1), one Sm(1), one Fe(5), one Fe(6), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), and two equivalent Fe(4) atoms. The Fe(4)-Fe(5) bond length is 2.76 Å. The Fe(4)-Fe(6) bond length is 2.76 Å. There is one shorter (2.48 Å) and one longer (2.49 Å) Fe(4)-Fe(4) bond length. In the fifth Fe site, Fe(5) is bonded in a 14-coordinate geometry to one Dy(1), one Fe(6), three equivalent Fe(2), three equivalent Fe(3), and six equivalent Fe(4) atoms. The Fe(5)-Fe(6) bond length is 2.39 Å. In the sixth Fe site, Fe(6) is bonded in a 14-coordinate geometry to one Sm(1), one Fe(5), three equivalent Fe(1), three equivalent Fe(3), and six equivalent Fe(4) atoms.