La6Fe9Al5 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one Fe(2), two equivalent Al(2), and three equivalent Al(1) atoms. In the second La site, La(2) is bonded in a 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(2), one Al(2), and four equivalent Al(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent La(2), one Fe(3), three equivalent Fe(1), four equivalent Fe(2), and two equivalent Al(1) atoms to form FeLa2Al2Fe8 cuboctahedra that share  a cornercorner with one Fe(3)Al4Fe8 cuboctahedra, corners with three equivalent Fe(1)La2Al2Fe8 cuboctahedra, edges with four equivalent Fe(2)La3Al3Fe6 cuboctahedra, faces with two equivalent Fe(3)Al4Fe8 cuboctahedra, faces with six equivalent Fe(2)La3Al3Fe6 cuboctahedra, and faces with seven equivalent Fe(1)La2Al2Fe8 cuboctahedra. In the second Fe site, Fe(2) is bonded to one La(1), two equivalent La(2), one Fe(2), one Fe(3), four equivalent Fe(1), and three equivalent Al(1) atoms to form distorted FeLa3Al3Fe6 cuboctahedra that share corners with seven equivalent Fe(2)La3Al3Fe6 cuboctahedra, edges with four equivalent Fe(1)La2Al2Fe8 cuboctahedra, faces with two equivalent Fe(3)Al4Fe8 cuboctahedra, faces with six equivalent Fe(1)La2Al2Fe8 cuboctahedra, and faces with six equivalent Fe(2)La3Al3Fe6 cuboctahedra. In the third Fe site, Fe(3) is bonded to four equivalent Fe(1), four equivalent Fe(2), and four equivalent Al(1) atoms to form FeAl4Fe8 cuboctahedra that share corners with four equivalent Fe(1)La2Al2Fe8 cuboctahedra, faces with eight equivalent Fe(1)La2Al2Fe8 cuboctahedra, and faces with eight equivalent Fe(2)La3Al3Fe6 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded in a distorted q6 geometry to two equivalent La(2) and eight equivalent La(1) atoms. In the second Al site, Al(1) is bonded in a 12-coordinate geometry to two equivalent La(2), three equivalent La(1), one Fe(3), two equivalent Fe(1), three equivalent Fe(2), and one Al(1) atom.
La6Fe9Al5 crystallizes in the tetragonal I4/mcm space group. There are two inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one Fe(2), two equivalent Al(2), and three equivalent Al(1) atoms. The La(1)-Fe(2) bond length is 3.21 Å. Both La(1)-Al(2) bond lengths are 3.38 Å. There are two shorter (3.35 Å) and one longer (3.41 Å) La(1)-Al(1) bond length. In the second La site, La(2) is bonded in a 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(2), one Al(2), and four equivalent Al(1) atoms. All La(2)-Fe(1) bond lengths are 3.13 Å. All La(2)-Fe(2) bond lengths are 3.27 Å. The La(2)-Al(2) bond length is 3.44 Å. All La(2)-Al(1) bond lengths are 3.30 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent La(2), one Fe(3), three equivalent Fe(1), four equivalent Fe(2), and two equivalent Al(1) atoms to form FeLa2Al2Fe8 cuboctahedra that share  a cornercorner with one Fe(3)Al4Fe8 cuboctahedra, corners with three equivalent Fe(1)La2Al2Fe8 cuboctahedra, edges with four equivalent Fe(2)La3Al3Fe6 cuboctahedra, faces with two equivalent Fe(3)Al4Fe8 cuboctahedra, faces with six equivalent Fe(2)La3Al3Fe6 cuboctahedra, and faces with seven equivalent Fe(1)La2Al2Fe8 cuboctahedra. The Fe(1)-Fe(3) bond length is 2.44 Å. All Fe(1)-Fe(1) bond lengths are 2.57 Å. There are two shorter (2.50 Å) and two longer (2.58 Å) Fe(1)-Fe(2) bond lengths. Both Fe(1)-Al(1) bond lengths are 2.63 Å. In the second Fe site, Fe(2) is bonded to one La(1), two equivalent La(2), one Fe(2), one Fe(3), four equivalent Fe(1), and three equivalent Al(1) atoms to form distorted FeLa3Al3Fe6 cuboctahedra that share corners with seven equivalent Fe(2)La3Al3Fe6 cuboctahedra, edges with four equivalent Fe(1)La2Al2Fe8 cuboctahedra, faces with two equivalent Fe(3)Al4Fe8 cuboctahedra, faces with six equivalent Fe(1)La2Al2Fe8 cuboctahedra, and faces with six equivalent Fe(2)La3Al3Fe6 cuboctahedra. The Fe(2)-Fe(2) bond length is 2.65 Å. The Fe(2)-Fe(3) bond length is 2.44 Å. There is one shorter (2.53 Å) and two longer (2.61 Å) Fe(2)-Al(1) bond lengths. In the third Fe site, Fe(3) is bonded to four equivalent Fe(1), four equivalent Fe(2), and four equivalent Al(1) atoms to form FeAl4Fe8 cuboctahedra that share corners with four equivalent Fe(1)La2Al2Fe8 cuboctahedra, faces with eight equivalent Fe(1)La2Al2Fe8 cuboctahedra, and faces with eight equivalent Fe(2)La3Al3Fe6 cuboctahedra. All Fe(3)-Al(1) bond lengths are 2.58 Å. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded in a distorted q6 geometry to two equivalent La(2) and eight equivalent La(1) atoms. In the second Al site, Al(1) is bonded in a 12-coordinate geometry to two equivalent La(2), three equivalent La(1), one Fe(3), two equivalent Fe(1), three equivalent Fe(2), and one Al(1) atom. The Al(1)-Al(1) bond length is 2.75 Å.