Sm2Fe13Al4 crystallizes in the trigonal R3m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 19-coordinate geometry to one Fe(4), three equivalent Fe(2), six equivalent Fe(1), six equivalent Fe(3), and three equivalent Al(2) atoms. In the second Sm site, Sm(2) is bonded in a 19-coordinate geometry to three equivalent Fe(3), six equivalent Fe(1), six equivalent Fe(2), one Al(1), and three equivalent Al(2) atoms. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one Sm(1), one Sm(2), one Fe(4), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), one Al(1), and two equivalent Al(2) atoms. In the second Fe site, Fe(2) is bonded to one Sm(1), two equivalent Sm(2), two equivalent Fe(3), four equivalent Fe(1), one Al(1), and two equivalent Al(2) atoms to form distorted FeSm3Al3Fe6 cuboctahedra that share corners with two equivalent Fe(2)Sm3Al3Fe6 cuboctahedra, corners with eight equivalent Fe(3)Sm3Al2Fe7 cuboctahedra,  an edgeedge with one Fe(3)Sm3Al2Fe7 cuboctahedra, edges with four equivalent Fe(2)Sm3Al3Fe6 cuboctahedra, faces with three equivalent Fe(3)Sm3Al2Fe7 cuboctahedra, and faces with four equivalent Fe(2)Sm3Al3Fe6 cuboctahedra. In the third Fe site, Fe(3) is bonded to one Sm(2), two equivalent Sm(1), one Fe(4), two equivalent Fe(2), four equivalent Fe(1), and two equivalent Al(2) atoms to form distorted FeSm3Al2Fe7 cuboctahedra that share corners with two equivalent Fe(3)Sm3Al2Fe7 cuboctahedra, corners with eight equivalent Fe(2)Sm3Al3Fe6 cuboctahedra,  an edgeedge with one Fe(2)Sm3Al3Fe6 cuboctahedra, edges with four equivalent Fe(3)Sm3Al2Fe7 cuboctahedra, faces with three equivalent Fe(2)Sm3Al3Fe6 cuboctahedra, and faces with four equivalent Fe(3)Sm3Al2Fe7 cuboctahedra. In the fourth Fe site, Fe(4) is bonded in a 14-coordinate geometry to one Sm(1), three equivalent Fe(3), six equivalent Fe(1), one Al(1), and three equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 14-coordinate geometry to one Sm(2), one Fe(4), three equivalent Fe(2), six equivalent Fe(1), and three equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Sm(1), one Sm(2), one Fe(4), two equivalent Fe(2), two equivalent Fe(3), four equivalent Fe(1), and one Al(1) atom.
Sm2Fe13Al4 crystallizes in the trigonal R3m space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a 19-coordinate geometry to one Fe(4), three equivalent Fe(2), six equivalent Fe(1), six equivalent Fe(3), and three equivalent Al(2) atoms. The Sm(1)-Fe(4) bond length is 3.14 Å. All Sm(1)-Fe(2) bond lengths are 3.11 Å. All Sm(1)-Fe(1) bond lengths are 3.06 Å. There are three shorter (3.17 Å) and three longer (3.33 Å) Sm(1)-Fe(3) bond lengths. All Sm(1)-Al(2) bond lengths are 3.31 Å. In the second Sm site, Sm(2) is bonded in a 19-coordinate geometry to three equivalent Fe(3), six equivalent Fe(1), six equivalent Fe(2), one Al(1), and three equivalent Al(2) atoms. All Sm(2)-Fe(3) bond lengths are 3.07 Å. All Sm(2)-Fe(1) bond lengths are 3.05 Å. There are three shorter (3.21 Å) and three longer (3.29 Å) Sm(2)-Fe(2) bond lengths. The Sm(2)-Al(1) bond length is 3.22 Å. All Sm(2)-Al(2) bond lengths are 3.39 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one Sm(1), one Sm(2), one Fe(4), two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(3), one Al(1), and two equivalent Al(2) atoms. The Fe(1)-Fe(4) bond length is 2.79 Å. Both Fe(1)-Fe(1) bond lengths are 2.48 Å. There is one shorter (2.51 Å) and one longer (2.74 Å) Fe(1)-Fe(2) bond length. There is one shorter (2.57 Å) and one longer (2.69 Å) Fe(1)-Fe(3) bond length. The Fe(1)-Al(1) bond length is 2.72 Å. There is one shorter (2.47 Å) and one longer (2.48 Å) Fe(1)-Al(2) bond length. In the second Fe site, Fe(2) is bonded to one Sm(1), two equivalent Sm(2), two equivalent Fe(3), four equivalent Fe(1), one Al(1), and two equivalent Al(2) atoms to form distorted FeSm3Al3Fe6 cuboctahedra that share corners with two equivalent Fe(2)Sm3Al3Fe6 cuboctahedra, corners with eight equivalent Fe(3)Sm3Al2Fe7 cuboctahedra,  an edgeedge with one Fe(3)Sm3Al2Fe7 cuboctahedra, edges with four equivalent Fe(2)Sm3Al3Fe6 cuboctahedra, faces with three equivalent Fe(3)Sm3Al2Fe7 cuboctahedra, and faces with four equivalent Fe(2)Sm3Al3Fe6 cuboctahedra. Both Fe(2)-Fe(3) bond lengths are 2.46 Å. The Fe(2)-Al(1) bond length is 2.66 Å. Both Fe(2)-Al(2) bond lengths are 2.50 Å. In the third Fe site, Fe(3) is bonded to one Sm(2), two equivalent Sm(1), one Fe(4), two equivalent Fe(2), four equivalent Fe(1), and two equivalent Al(2) atoms to form distorted FeSm3Al2Fe7 cuboctahedra that share corners with two equivalent Fe(3)Sm3Al2Fe7 cuboctahedra, corners with eight equivalent Fe(2)Sm3Al3Fe6 cuboctahedra,  an edgeedge with one Fe(2)Sm3Al3Fe6 cuboctahedra, edges with four equivalent Fe(3)Sm3Al2Fe7 cuboctahedra, faces with three equivalent Fe(2)Sm3Al3Fe6 cuboctahedra, and faces with four equivalent Fe(3)Sm3Al2Fe7 cuboctahedra. The Fe(3)-Fe(4) bond length is 2.68 Å. Both Fe(3)-Al(2) bond lengths are 2.45 Å. In the fourth Fe site, Fe(4) is bonded in a 14-coordinate geometry to one Sm(1), three equivalent Fe(3), six equivalent Fe(1), one Al(1), and three equivalent Al(2) atoms. The Fe(4)-Al(1) bond length is 2.40 Å. All Fe(4)-Al(2) bond lengths are 2.54 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 14-coordinate geometry to one Sm(2), one Fe(4), three equivalent Fe(2), six equivalent Fe(1), and three equivalent Al(2) atoms. All Al(1)-Al(2) bond lengths are 2.73 Å. In the second Al site, Al(2) is bonded in a 9-coordinate geometry to one Sm(1), one Sm(2), one Fe(4), two equivalent Fe(2), two equivalent Fe(3), four equivalent Fe(1), and one Al(1) atom.