Fe6Ga2C crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a single-bond geometry to four equivalent Fe(3), four equivalent Ga(1), and one C(1) atom. In the second Fe site, Fe(2) is bonded in a linear geometry to four equivalent Ga(1) and two equivalent C(1) atoms. In the third Fe site, Fe(3) is bonded to four equivalent Fe(1), four equivalent Fe(3), and four equivalent Ga(1) atoms to form FeGa4Fe8 cuboctahedra that share corners with four equivalent Fe(3)Ga4Fe8 cuboctahedra, corners with four equivalent C(1)Fe6 octahedra, edges with eight equivalent Ga(1)Fe12 cuboctahedra, faces with four equivalent Ga(1)Fe12 cuboctahedra, and faces with eight equivalent Fe(3)Ga4Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 49°. Ga(1) is bonded to four equivalent Fe(1), four equivalent Fe(2), and four equivalent Fe(3) atoms to form GaFe12 cuboctahedra that share corners with twelve equivalent Ga(1)Fe12 cuboctahedra, edges with eight equivalent Fe(3)Ga4Fe8 cuboctahedra, faces with four equivalent Fe(3)Ga4Fe8 cuboctahedra, faces with six equivalent Ga(1)Fe12 cuboctahedra, and faces with four equivalent C(1)Fe6 octahedra. C(1) is bonded to two equivalent Fe(1) and four equivalent Fe(2) atoms to form CFe6 octahedra that share corners with eight equivalent Fe(3)Ga4Fe8 cuboctahedra, corners with four equivalent C(1)Fe6 octahedra, and faces with eight equivalent Ga(1)Fe12 cuboctahedra. The corner-sharing octahedra are not tilted.
Fe6Ga2C crystallizes in the tetragonal P4/mmm space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a single-bond geometry to four equivalent Fe(3), four equivalent Ga(1), and one C(1) atom. All Fe(1)-Fe(3) bond lengths are 2.50 Å. All Fe(1)-Ga(1) bond lengths are 2.67 Å. The Fe(1)-C(1) bond length is 1.92 Å. In the second Fe site, Fe(2) is bonded in a linear geometry to four equivalent Ga(1) and two equivalent C(1) atoms. All Fe(2)-Ga(1) bond lengths are 2.61 Å. Both Fe(2)-C(1) bond lengths are 1.89 Å. In the third Fe site, Fe(3) is bonded to four equivalent Fe(1), four equivalent Fe(3), and four equivalent Ga(1) atoms to form FeGa4Fe8 cuboctahedra that share corners with four equivalent Fe(3)Ga4Fe8 cuboctahedra, corners with four equivalent C(1)Fe6 octahedra, edges with eight equivalent Ga(1)Fe12 cuboctahedra, faces with four equivalent Ga(1)Fe12 cuboctahedra, and faces with eight equivalent Fe(3)Ga4Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 49°. All Fe(3)-Fe(3) bond lengths are 2.67 Å. All Fe(3)-Ga(1) bond lengths are 2.58 Å. Ga(1) is bonded to four equivalent Fe(1), four equivalent Fe(2), and four equivalent Fe(3) atoms to form GaFe12 cuboctahedra that share corners with twelve equivalent Ga(1)Fe12 cuboctahedra, edges with eight equivalent Fe(3)Ga4Fe8 cuboctahedra, faces with four equivalent Fe(3)Ga4Fe8 cuboctahedra, faces with six equivalent Ga(1)Fe12 cuboctahedra, and faces with four equivalent C(1)Fe6 octahedra. C(1) is bonded to two equivalent Fe(1) and four equivalent Fe(2) atoms to form CFe6 octahedra that share corners with eight equivalent Fe(3)Ga4Fe8 cuboctahedra, corners with four equivalent C(1)Fe6 octahedra, and faces with eight equivalent Ga(1)Fe12 cuboctahedra. The corner-sharing octahedra are not tilted.