La6Fe9Al4As 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 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(3), four equivalent Al(1), and one As(1) atom. In the second La site, La(2) is bonded in a 6-coordinate geometry to one Fe(3), three equivalent Al(1), and two equivalent As(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent La(1), one Fe(2), three equivalent Fe(1), four equivalent Fe(3), and two equivalent Al(1) atoms to form FeLa2Al2Fe8 cuboctahedra that share  a cornercorner with one Fe(2)Al4Fe8 cuboctahedra, corners with three equivalent Fe(1)La2Al2Fe8 cuboctahedra, faces with two equivalent Fe(2)Al4Fe8 cuboctahedra, and faces with seven equivalent Fe(1)La2Al2Fe8 cuboctahedra. In the second Fe site, Fe(2) is bonded to four equivalent Fe(1), four equivalent Fe(3), and four equivalent Al(1) atoms to form a mixture of corner and face-sharing FeAl4Fe8 cuboctahedra. In the third Fe site, Fe(3) is bonded in a 12-coordinate geometry to one La(2), two equivalent La(1), one Fe(2), one Fe(3), four equivalent Fe(1), and three equivalent Al(1) atoms. Al(1) is bonded in a 12-coordinate geometry to two equivalent La(1), three equivalent La(2), one Fe(2), two equivalent Fe(1), three equivalent Fe(3), and one Al(1) atom. As(1) is bonded in a distorted q6 geometry to two equivalent La(1) and eight equivalent La(2) atoms.
La6Fe9Al4As 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 13-coordinate geometry to four equivalent Fe(1), four equivalent Fe(3), four equivalent Al(1), and one As(1) atom. All La(1)-Fe(1) bond lengths are 3.09 Å. All La(1)-Fe(3) bond lengths are 3.23 Å. All La(1)-Al(1) bond lengths are 3.28 Å. The La(1)-As(1) bond length is 3.44 Å. In the second La site, La(2) is bonded in a 6-coordinate geometry to one Fe(3), three equivalent Al(1), and two equivalent As(1) atoms. The La(2)-Fe(3) bond length is 3.18 Å. There are two shorter (3.32 Å) and one longer (3.40 Å) La(2)-Al(1) bond length. Both La(2)-As(1) bond lengths are 3.37 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent La(1), one Fe(2), three equivalent Fe(1), four equivalent Fe(3), and two equivalent Al(1) atoms to form FeLa2Al2Fe8 cuboctahedra that share  a cornercorner with one Fe(2)Al4Fe8 cuboctahedra, corners with three equivalent Fe(1)La2Al2Fe8 cuboctahedra, faces with two equivalent Fe(2)Al4Fe8 cuboctahedra, and faces with seven equivalent Fe(1)La2Al2Fe8 cuboctahedra. The Fe(1)-Fe(2) bond length is 2.42 Å. All Fe(1)-Fe(1) bond lengths are 2.56 Å. There are two shorter (2.49 Å) and two longer (2.56 Å) Fe(1)-Fe(3) bond lengths. Both Fe(1)-Al(1) bond lengths are 2.61 Å. In the second Fe site, Fe(2) is bonded to four equivalent Fe(1), four equivalent Fe(3), and four equivalent Al(1) atoms to form a mixture of corner and face-sharing FeAl4Fe8 cuboctahedra. All Fe(2)-Fe(3) bond lengths are 2.43 Å. All Fe(2)-Al(1) bond lengths are 2.57 Å. In the third Fe site, Fe(3) is bonded in a 12-coordinate geometry to one La(2), two equivalent La(1), one Fe(2), one Fe(3), four equivalent Fe(1), and three equivalent Al(1) atoms. The Fe(3)-Fe(3) bond length is 2.65 Å. There is one shorter (2.52 Å) and two longer (2.59 Å) Fe(3)-Al(1) bond lengths. Al(1) is bonded in a 12-coordinate geometry to two equivalent La(1), three equivalent La(2), one Fe(2), two equivalent Fe(1), three equivalent Fe(3), and one Al(1) atom. The Al(1)-Al(1) bond length is 2.73 Å. As(1) is bonded in a distorted q6 geometry to two equivalent La(1) and eight equivalent La(2) atoms.