DOE OSTI2020
LaFe10Ga3C crystallizes in the orthorhombic Fmm2 space group. The structure is three-dimensional. La is bonded in a distorted linear geometry to ten Fe, six Ga, and two equivalent C atoms. There are a spread of La–Fe bond distances ranging from 3.46–3.51 Å. There are a spread of La–Ga bond distances ranging from 3.38–3.43 Å. There are one shorter (2.88 Å) and one longer (2.89 Å) La–C bond lengths. There are nine inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to four Fe, three Ga, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.48–2.60 Å. There are two shorter (2.57 Å) and one longer (2.66 Å) Fe–Ga bond lengths. The Fe–C bond length is 1.85 Å. In the second Fe site, Fe is bonded in a single-bond geometry to four Fe, three Ga, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.47–2.63 Å. There are a spread of Fe–Ga bond distances ranging from 2.55–2.67 Å. The Fe–C bond length is 1.86 Å. In the third Fe site, Fe is bonded to ten Fe and two equivalent Ga atoms to form FeGa2Fe10 cuboctahedra that share corners with four FeLa2Ga3Fe7 cuboctahedra, corners with four equivalent CLa2Fe4 octahedra, and faces with ten FeLa2Ga3Fe7 cuboctahedra. The corner-sharing octahedral tilt angles are 29°. There are a spread of Fe–Fe bond distances ranging from 2.39–2.49 Å. Both Fe–Ga bond lengths are 2.58 Å. In the fourth Fe site, Fe is bonded to eight Fe and four Ga atoms to form FeGa4Fe8 cuboctahedra that share corners with six FeLa2Ga4Fe6 cuboctahedra, corners with four equivalent CLa2Fe4 octahedra, and faces with ten FeLa2Ga3Fe7 cuboctahedra. The corner-sharing octahedral tilt angles are 30°. There are two shorter (2.42 Å) and two longer (2.43 Å) Fe–Fe bond lengths. There are two shorter (2.58 Å) and two longer (2.59 Å) Fe–Ga bond lengths. In the fifth Fe site, Fe is bonded to two equivalent La, seven Fe, and three Ga atoms to form distorted FeLa2Ga3Fe7 cuboctahedra that share corners with ten FeGa2Fe10 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, edges with four equivalent FeLa2Ga4Fe6 cuboctahedra, edges with two equivalent CLa2Fe4 octahedra, and faces with ten FeGa2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 76°. There are a spread of Fe–Fe bond distances ranging from 2.49–2.55 Å. There are one shorter (2.55 Å) and two longer (2.61 Å) Fe–Ga bond lengths. In the sixth Fe site, Fe is bonded to two equivalent La, six Fe, and four Ga atoms to form distorted FeLa2Ga4Fe6 cuboctahedra that share corners with ten FeGa4Fe8 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, edges with six FeLa2Ga3Fe7 cuboctahedra, edges with two equivalent CLa2Fe4 octahedra, and faces with nine FeGa2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 75°. There are two shorter (2.57 Å) and one longer (2.60 Å) Fe–Fe bond lengths. There are a spread of Fe–Ga bond distances ranging from 2.51–2.59 Å. In the seventh Fe site, Fe is bonded to two equivalent La, seven Fe, and three Ga atoms to form distorted FeLa2Ga3Fe7 cuboctahedra that share corners with twelve FeGa2Fe10 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, edges with four equivalent FeLa2Ga2Fe8 cuboctahedra, edges with two equivalent CLa2Fe4 octahedra, and faces with eight FeGa4Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 76°. There are one shorter (2.55 Å) and one longer (2.65 Å) Fe–Fe bond lengths. There are one shorter (2.52 Å) and two longer (2.60 Å) Fe–Ga bond lengths. In the eighth Fe site, Fe is bonded to two equivalent La, eight Fe, and two Ga atoms to form distorted FeLa2Ga2Fe8 cuboctahedra that share corners with ten FeGa4Fe8 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, edges with four equivalent FeLa2Ga3Fe7 cuboctahedra, edges with two equivalent CLa2Fe4 octahedra, and faces with nine FeGa2Fe10 cuboctahedra. The corner-sharing octahedral tilt angles are 76°. There are two shorter (2.59 Å) and one longer (2.65 Å) Fe–Fe bond lengths. There are one shorter (2.51 Å) and one longer (2.54 Å) Fe–Ga bond lengths. In the ninth Fe site, Fe is bonded to two equivalent La, nine Fe, and one Ga atom to form distorted FeLa2GaFe9 cuboctahedra that share corners with thirteen FeGa4Fe8 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, edges with two equivalent FeLa2Ga4Fe6 cuboctahedra, faces with eleven FeGa4Fe8 cuboctahedra, and faces with two equivalent CLa2Fe4 octahedra. The corner-sharing octahedral tilt angles are 63°. The Fe–Ga bond length is 2.72 Å. There are three inequivalent Ga sites. In the first Ga site, Ga is bonded in a 12-coordinate geometry to two equivalent La, nine Fe, and one Ga atom. The Ga–Ga bond length is 2.83 Å. In the second Ga site, Ga is bonded in a 12-coordinate geometry to two equivalent La and ten Fe atoms. In the third Ga site, Ga is bonded in a 12-coordinate geometry to two equivalent La, nine Fe, and one Ga atom. C is bonded to two equivalent La and four Fe atoms to form distorted CLa2Fe4 octahedra that share corners with fourteen FeGa2Fe10 cuboctahedra, corners with two equivalent CLa2Fe4 octahedra, edges with eight FeLa2Ga2Fe8 cuboctahedra, and faces with two equivalent FeLa2GaFe9 cuboctahedra. The corner-sharing octahedral tilt angles are 0°.