Sm4(FeB2)3 crystallizes in the trigonal R-3m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to four equivalent Sm(2), three equivalent Fe(1), and six equivalent B(1) atoms. In the second Sm site, Sm(2) is bonded in a 16-coordinate geometry to four equivalent Sm(1), three equivalent Fe(1), three equivalent Fe(2), and six equivalent B(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to six equivalent Sm(1), six equivalent Sm(2), and two equivalent Fe(2) atoms. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to three equivalent Sm(2), one Fe(1), and six equivalent B(1) atoms. B(1) is bonded in a 9-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), two equivalent Fe(2), and three equivalent B(1) atoms.
Sm4(FeB2)3 crystallizes in the trigonal R-3m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 6-coordinate geometry to four equivalent Sm(2), three equivalent Fe(1), and six equivalent B(1) atoms. There are three shorter (3.09 Å) and one longer (3.45 Å) Sm(1)-Sm(2) bond length. All Sm(1)-Fe(1) bond lengths are 3.53 Å. All Sm(1)-B(1) bond lengths are 2.69 Å. In the second Sm site, Sm(2) is bonded in a 16-coordinate geometry to four equivalent Sm(1), three equivalent Fe(1), three equivalent Fe(2), and six equivalent B(1) atoms. All Sm(2)-Fe(1) bond lengths are 3.55 Å. All Sm(2)-Fe(2) bond lengths are 3.20 Å. All Sm(2)-B(1) bond lengths are 2.67 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to six equivalent Sm(1), six equivalent Sm(2), and two equivalent Fe(2) atoms. Both Fe(1)-Fe(2) bond lengths are 2.57 Å. In the second Fe site, Fe(2) is bonded in a 6-coordinate geometry to three equivalent Sm(2), one Fe(1), and six equivalent B(1) atoms. All Fe(2)-B(1) bond lengths are 2.13 Å. B(1) is bonded in a 9-coordinate geometry to two equivalent Sm(1), two equivalent Sm(2), two equivalent Fe(2), and three equivalent B(1) atoms. There are two shorter (1.78 Å) and one longer (1.79 Å) B(1)-B(1) bond length.