LaFe9Ga4C crystallizes in the tetragonal I4/mcm space group. La(1) is bonded in a distorted linear geometry to eight equivalent Fe(2), eight equivalent Ga(1), and two equivalent C(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(3) is bonded to four equivalent Fe(1), four equivalent Fe(2), and four equivalent Ga(1) atoms to form FeGa4Fe8 cuboctahedra that share corners with four equivalent Fe(2)La2Ga4Fe6 cuboctahedra, corners with four equivalent C(1)La2Fe4 octahedra, and faces with eight equivalent Fe(2)La2Ga4Fe6 cuboctahedra. The corner-sharing octahedral tilt angles are 30°. In the second Fe site, Fe(1) is bonded in a single-bond geometry to one Fe(3), two equivalent Fe(2), four equivalent Ga(1), and one C(1) atom. In the third Fe site, Fe(2) is bonded to two equivalent La(1), one Fe(3), two equivalent Fe(1), three equivalent Fe(2), and four equivalent Ga(1) atoms to form distorted FeLa2Ga4Fe6 cuboctahedra that share  a cornercorner with one Fe(3)Ga4Fe8 cuboctahedra, corners with seven equivalent Fe(2)La2Ga4Fe6 cuboctahedra, corners with two equivalent C(1)La2Fe4 octahedra, edges with four equivalent Fe(2)La2Ga4Fe6 cuboctahedra, edges with two equivalent C(1)La2Fe4 octahedra, faces with two equivalent Fe(3)Ga4Fe8 cuboctahedra, and faces with five equivalent Fe(2)La2Ga4Fe6 cuboctahedra. The corner-sharing octahedral tilt angles are 75°. Ga(1) is bonded in a 12-coordinate geometry to two equivalent La(1), one Fe(3), four equivalent Fe(1), four equivalent Fe(2), and one Ga(1) atom. C(1) is bonded to two equivalent La(1) and four equivalent Fe(1) atoms to form distorted CLa2Fe4 octahedra that share corners with four equivalent Fe(3)Ga4Fe8 cuboctahedra, corners with eight equivalent Fe(2)La2Ga4Fe6 cuboctahedra, corners with two equivalent C(1)La2Fe4 octahedra, and edges with eight equivalent Fe(2)La2Ga4Fe6 cuboctahedra. The corner-sharing octahedra are not tilted.
LaFe9Ga4C crystallizes in the tetragonal I4/mcm space group. La(1) is bonded in a distorted linear geometry to eight equivalent Fe(2), eight equivalent Ga(1), and two equivalent C(1) atoms. All La(1)-Fe(2) bond lengths are 3.50 Å. All La(1)-Ga(1) bond lengths are 3.40 Å. Both La(1)-C(1) bond lengths are 2.90 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(3) is bonded to four equivalent Fe(1), four equivalent Fe(2), and four equivalent Ga(1) atoms to form FeGa4Fe8 cuboctahedra that share corners with four equivalent Fe(2)La2Ga4Fe6 cuboctahedra, corners with four equivalent C(1)La2Fe4 octahedra, and faces with eight equivalent Fe(2)La2Ga4Fe6 cuboctahedra. The corner-sharing octahedral tilt angles are 30°. All Fe(3)-Fe(1) bond lengths are 2.47 Å. All Fe(3)-Fe(2) bond lengths are 2.39 Å. All Fe(3)-Ga(1) bond lengths are 2.59 Å. In the second Fe site, Fe(1) is bonded in a single-bond geometry to one Fe(3), two equivalent Fe(2), four equivalent Ga(1), and one C(1) atom. Both Fe(1)-Fe(2) bond lengths are 2.54 Å. There are two shorter (2.55 Å) and two longer (2.66 Å) Fe(1)-Ga(1) bond lengths. The Fe(1)-C(1) bond length is 1.85 Å. In the third Fe site, Fe(2) is bonded to two equivalent La(1), one Fe(3), two equivalent Fe(1), three equivalent Fe(2), and four equivalent Ga(1) atoms to form distorted FeLa2Ga4Fe6 cuboctahedra that share  a cornercorner with one Fe(3)Ga4Fe8 cuboctahedra, corners with seven equivalent Fe(2)La2Ga4Fe6 cuboctahedra, corners with two equivalent C(1)La2Fe4 octahedra, edges with four equivalent Fe(2)La2Ga4Fe6 cuboctahedra, edges with two equivalent C(1)La2Fe4 octahedra, faces with two equivalent Fe(3)Ga4Fe8 cuboctahedra, and faces with five equivalent Fe(2)La2Ga4Fe6 cuboctahedra. The corner-sharing octahedral tilt angles are 75°. There are two shorter (2.52 Å) and one longer (2.56 Å) Fe(2)-Fe(2) bond length. There are a spread of Fe(2)-Ga(1) bond distances ranging from 2.52-2.58 Å. Ga(1) is bonded in a 12-coordinate geometry to two equivalent La(1), one Fe(3), four equivalent Fe(1), four equivalent Fe(2), and one Ga(1) atom. The Ga(1)-Ga(1) bond length is 2.84 Å. C(1) is bonded to two equivalent La(1) and four equivalent Fe(1) atoms to form distorted CLa2Fe4 octahedra that share corners with four equivalent Fe(3)Ga4Fe8 cuboctahedra, corners with eight equivalent Fe(2)La2Ga4Fe6 cuboctahedra, corners with two equivalent C(1)La2Fe4 octahedra, and edges with eight equivalent Fe(2)La2Ga4Fe6 cuboctahedra. The corner-sharing octahedra are not tilted.