Sm2Fe17B3 crystallizes in the trigonal R-3m space group. Sm(1) is bonded in a distorted trigonal planar geometry to one Fe(4), three equivalent Fe(1), and three equivalent B(1) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Sm(1), two equivalent Fe(4), four equivalent Fe(2), and four equivalent Fe(3) atoms to form FeSm2Fe10 cuboctahedra that share corners with four equivalent Fe(1)Sm2Fe10 cuboctahedra, corners with two equivalent B(1)Sm2Fe4 octahedra, faces with four equivalent Fe(1)Sm2Fe10 cuboctahedra, and faces with four equivalent B(1)Sm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. In the second Fe site, Fe(2) is bonded in a single-bond geometry to two equivalent Fe(1), two equivalent Fe(4), and one B(1) atom. In the third Fe site, Fe(3) is bonded in a single-bond geometry to one Fe(4), two equivalent Fe(1), and one B(1) atom. In the fourth Fe site, Fe(4) is bonded in a 14-coordinate geometry to one Sm(1), one Fe(4), three equivalent Fe(1), three equivalent Fe(3), and six equivalent Fe(2) atoms. B(1) is bonded to two equivalent Sm(1), two equivalent Fe(2), and two equivalent Fe(3) atoms to form BSm2Fe4 octahedra that share corners with two equivalent Fe(1)Sm2Fe10 cuboctahedra, corners with four equivalent B(1)Sm2Fe4 octahedra, and faces with four equivalent Fe(1)Sm2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 60°.
Sm2Fe17B3 crystallizes in the trigonal R-3m space group. Sm(1) is bonded in a distorted trigonal planar geometry to one Fe(4), three equivalent Fe(1), and three equivalent B(1) atoms. The Sm(1)-Fe(4) bond length is 3.10 Å. All Sm(1)-Fe(1) bond lengths are 3.36 Å. All Sm(1)-B(1) bond lengths are 2.54 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Sm(1), two equivalent Fe(4), four equivalent Fe(2), and four equivalent Fe(3) atoms to form FeSm2Fe10 cuboctahedra that share corners with four equivalent Fe(1)Sm2Fe10 cuboctahedra, corners with two equivalent B(1)Sm2Fe4 octahedra, faces with four equivalent Fe(1)Sm2Fe10 cuboctahedra, and faces with four equivalent B(1)Sm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 44°. Both Fe(1)-Fe(4) bond lengths are 2.69 Å. All Fe(1)-Fe(2) bond lengths are 2.45 Å. All Fe(1)-Fe(3) bond lengths are 2.51 Å. In the second Fe site, Fe(2) is bonded in a single-bond geometry to two equivalent Fe(1), two equivalent Fe(4), and one B(1) atom. Both Fe(2)-Fe(4) bond lengths are 2.73 Å. The Fe(2)-B(1) bond length is 1.94 Å. In the third Fe site, Fe(3) is bonded in a single-bond geometry to one Fe(4), two equivalent Fe(1), and one B(1) atom. The Fe(3)-Fe(4) bond length is 2.67 Å. The Fe(3)-B(1) bond length is 1.97 Å. In the fourth Fe site, Fe(4) is bonded in a 14-coordinate geometry to one Sm(1), one Fe(4), three equivalent Fe(1), three equivalent Fe(3), and six equivalent Fe(2) atoms. The Fe(4)-Fe(4) bond length is 2.38 Å. B(1) is bonded to two equivalent Sm(1), two equivalent Fe(2), and two equivalent Fe(3) atoms to form BSm2Fe4 octahedra that share corners with two equivalent Fe(1)Sm2Fe10 cuboctahedra, corners with four equivalent B(1)Sm2Fe4 octahedra, and faces with four equivalent Fe(1)Sm2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 60°.