La6Fe11Al3 crystallizes in the tetragonal I4cm space group. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one Fe(1), two equivalent Al(1), and three equivalent Al(2) atoms. In the second La site, La(2) is bonded in a 6-coordinate geometry to one Fe(2), three equivalent Fe(5), and two equivalent Al(1) atoms. In the third La site, La(3) is bonded in a 13-coordinate geometry to four equivalent Fe(2), four equivalent Fe(3), four equivalent Fe(5), and one Al(1) atom. In the fourth La site, La(4) is bonded in a 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(3), one Al(1), and four equivalent Al(2) atoms. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one La(1), two equivalent La(4), one Fe(2), one Fe(4), four equivalent Fe(3), and three equivalent Al(2) atoms. In the second Fe site, Fe(2) is bonded to one La(2), two equivalent La(3), one Fe(1), one Fe(4), three equivalent Fe(5), and four equivalent Fe(3) atoms to form distorted FeLa3Fe9 cuboctahedra that share corners with two equivalent Fe(2)La3Fe9 cuboctahedra, corners with five equivalent Fe(5)La5Fe7 cuboctahedra, edges with four equivalent Fe(3)La2AlFe9 cuboctahedra, faces with two equivalent Fe(4)Al2Fe10 cuboctahedra, faces with three equivalent Fe(5)La5Fe7 cuboctahedra, faces with five equivalent Fe(2)La3Fe9 cuboctahedra, and faces with six equivalent Fe(3)La2AlFe9 cuboctahedra. In the third Fe site, Fe(3) is bonded to one La(3), one La(4), one Fe(4), one Fe(5), two equivalent Fe(1), two equivalent Fe(2), three equivalent Fe(3), and one Al(2) atom to form FeLa2AlFe9 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)La5Fe7 cuboctahedra, corners with three equivalent Fe(3)La2AlFe9 cuboctahedra, edges with two equivalent Fe(2)La3Fe9 cuboctahedra, faces with two equivalent Fe(4)Al2Fe10 cuboctahedra, faces with three equivalent Fe(2)La3Fe9 cuboctahedra, faces with four equivalent Fe(5)La5Fe7 cuboctahedra, and faces with seven equivalent Fe(3)La2AlFe9 cuboctahedra. In the fourth Fe site, Fe(4) is bonded to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(5), four equivalent Fe(3), and two equivalent Al(2) atoms to form FeAl2Fe10 cuboctahedra that share corners with two equivalent Fe(5)La5Fe7 cuboctahedra, corners with four equivalent Fe(3)La2AlFe9 cuboctahedra, faces with two equivalent Fe(5)La5Fe7 cuboctahedra, faces with four equivalent Fe(2)La3Fe9 cuboctahedra, and faces with eight equivalent Fe(3)La2AlFe9 cuboctahedra. In the fifth Fe site, Fe(5) is bonded to two equivalent La(3), three equivalent La(2), one Fe(4), one Fe(5), two equivalent Fe(3), and three equivalent Fe(2) atoms to form distorted FeLa5Fe7 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)La5Fe7 cuboctahedra, corners with four equivalent Fe(3)La2AlFe9 cuboctahedra, corners with five equivalent Fe(2)La3Fe9 cuboctahedra,  a faceface with one Fe(4)Al2Fe10 cuboctahedra, faces with three equivalent Fe(2)La3Fe9 cuboctahedra, faces with five equivalent Fe(5)La5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)La2AlFe9 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted q6 geometry to one La(3), one La(4), four equivalent La(1), and four equivalent La(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent La(4), three equivalent La(1), one Fe(4), two equivalent Fe(3), three equivalent Fe(1), and one Al(2) atom.
La6Fe11Al3 crystallizes in the tetragonal I4cm space group. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one Fe(1), two equivalent Al(1), and three equivalent Al(2) atoms. The La(1)-Fe(1) bond length is 3.20 Å. Both La(1)-Al(1) bond lengths are 3.36 Å. There are two shorter (3.33 Å) and one longer (3.38 Å) La(1)-Al(2) bond length. In the second La site, La(2) is bonded in a 6-coordinate geometry to one Fe(2), three equivalent Fe(5), and two equivalent Al(1) atoms. The La(2)-Fe(2) bond length is 3.04 Å. There are two shorter (3.23 Å) and one longer (3.37 Å) La(2)-Fe(5) bond length. Both La(2)-Al(1) bond lengths are 3.41 Å. In the third La site, La(3) is bonded in a 13-coordinate geometry to four equivalent Fe(2), four equivalent Fe(3), four equivalent Fe(5), and one Al(1) atom. All La(3)-Fe(2) bond lengths are 3.21 Å. All La(3)-Fe(3) bond lengths are 3.08 Å. All La(3)-Fe(5) bond lengths are 3.30 Å. The La(3)-Al(1) bond length is 3.46 Å. In the fourth La site, La(4) is bonded in a 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(3), one Al(1), and four equivalent Al(2) atoms. All La(4)-Fe(1) bond lengths are 3.24 Å. All La(4)-Fe(3) bond lengths are 3.12 Å. The La(4)-Al(1) bond length is 3.44 Å. All La(4)-Al(2) bond lengths are 3.28 Å. There are five inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 12-coordinate geometry to one La(1), two equivalent La(4), one Fe(2), one Fe(4), four equivalent Fe(3), and three equivalent Al(2) atoms. The Fe(1)-Fe(2) bond length is 2.69 Å. The Fe(1)-Fe(4) bond length is 2.43 Å. There are two shorter (2.49 Å) and two longer (2.57 Å) Fe(1)-Fe(3) bond lengths. There is one shorter (2.53 Å) and two longer (2.59 Å) Fe(1)-Al(2) bond lengths. In the second Fe site, Fe(2) is bonded to one La(2), two equivalent La(3), one Fe(1), one Fe(4), three equivalent Fe(5), and four equivalent Fe(3) atoms to form distorted FeLa3Fe9 cuboctahedra that share corners with two equivalent Fe(2)La3Fe9 cuboctahedra, corners with five equivalent Fe(5)La5Fe7 cuboctahedra, edges with four equivalent Fe(3)La2AlFe9 cuboctahedra, faces with two equivalent Fe(4)Al2Fe10 cuboctahedra, faces with three equivalent Fe(5)La5Fe7 cuboctahedra, faces with five equivalent Fe(2)La3Fe9 cuboctahedra, and faces with six equivalent Fe(3)La2AlFe9 cuboctahedra. The Fe(2)-Fe(4) bond length is 2.46 Å. There is one shorter (2.53 Å) and two longer (2.57 Å) Fe(2)-Fe(5) bond lengths. There are two shorter (2.48 Å) and two longer (2.59 Å) Fe(2)-Fe(3) bond lengths. In the third Fe site, Fe(3) is bonded to one La(3), one La(4), one Fe(4), one Fe(5), two equivalent Fe(1), two equivalent Fe(2), three equivalent Fe(3), and one Al(2) atom to form FeLa2AlFe9 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)La5Fe7 cuboctahedra, corners with three equivalent Fe(3)La2AlFe9 cuboctahedra, edges with two equivalent Fe(2)La3Fe9 cuboctahedra, faces with two equivalent Fe(4)Al2Fe10 cuboctahedra, faces with three equivalent Fe(2)La3Fe9 cuboctahedra, faces with four equivalent Fe(5)La5Fe7 cuboctahedra, and faces with seven equivalent Fe(3)La2AlFe9 cuboctahedra. The Fe(3)-Fe(4) bond length is 2.42 Å. The Fe(3)-Fe(5) bond length is 2.63 Å. There is one shorter (2.54 Å) and two longer (2.55 Å) Fe(3)-Fe(3) bond lengths. The Fe(3)-Al(2) bond length is 2.63 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent Fe(1), two equivalent Fe(2), two equivalent Fe(5), four equivalent Fe(3), and two equivalent Al(2) atoms to form FeAl2Fe10 cuboctahedra that share corners with two equivalent Fe(5)La5Fe7 cuboctahedra, corners with four equivalent Fe(3)La2AlFe9 cuboctahedra, faces with two equivalent Fe(5)La5Fe7 cuboctahedra, faces with four equivalent Fe(2)La3Fe9 cuboctahedra, and faces with eight equivalent Fe(3)La2AlFe9 cuboctahedra. Both Fe(4)-Fe(5) bond lengths are 2.53 Å. Both Fe(4)-Al(2) bond lengths are 2.59 Å. In the fifth Fe site, Fe(5) is bonded to two equivalent La(3), three equivalent La(2), one Fe(4), one Fe(5), two equivalent Fe(3), and three equivalent Fe(2) atoms to form distorted FeLa5Fe7 cuboctahedra that share  a cornercorner with one Fe(4)Al2Fe10 cuboctahedra, corners with two equivalent Fe(5)La5Fe7 cuboctahedra, corners with four equivalent Fe(3)La2AlFe9 cuboctahedra, corners with five equivalent Fe(2)La3Fe9 cuboctahedra,  a faceface with one Fe(4)Al2Fe10 cuboctahedra, faces with three equivalent Fe(2)La3Fe9 cuboctahedra, faces with five equivalent Fe(5)La5Fe7 cuboctahedra, and faces with eight equivalent Fe(3)La2AlFe9 cuboctahedra. The Fe(5)-Fe(5) bond length is 2.61 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted q6 geometry to one La(3), one La(4), four equivalent La(1), and four equivalent La(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent La(4), three equivalent La(1), one Fe(4), two equivalent Fe(3), three equivalent Fe(1), and one Al(2) atom. The Al(2)-Al(2) bond length is 2.72 Å.