Al3BC3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent C(2) and three equivalent C(1) atoms to form distorted AlC5 trigonal bipyramids that share corners with six equivalent Al(1)C5 trigonal bipyramids and edges with six equivalent Al(2)C4 tetrahedra. In the second Al site, Al(2) is bonded to one C(1) and three equivalent C(2) atoms to form AlC4 tetrahedra that share corners with seven equivalent Al(2)C4 tetrahedra and edges with three equivalent Al(1)C5 trigonal bipyramids. B(1) is bonded in a linear geometry to two equivalent C(2) atoms. There are two inequivalent C sites. In the first C site, C(1) is bonded to two equivalent Al(2) and three equivalent Al(1) atoms to form corner-sharing CAl5 trigonal bipyramids. In the second C site, C(2) is bonded in a 5-coordinate geometry to one Al(1), three equivalent Al(2), and one B(1) atom.
Al3BC3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent C(2) and three equivalent C(1) atoms to form distorted AlC5 trigonal bipyramids that share corners with six equivalent Al(1)C5 trigonal bipyramids and edges with six equivalent Al(2)C4 tetrahedra. Both Al(1)-C(2) bond lengths are 2.53 Å. All Al(1)-C(1) bond lengths are 1.98 Å. In the second Al site, Al(2) is bonded to one C(1) and three equivalent C(2) atoms to form AlC4 tetrahedra that share corners with seven equivalent Al(2)C4 tetrahedra and edges with three equivalent Al(1)C5 trigonal bipyramids. The Al(2)-C(1) bond length is 2.03 Å. All Al(2)-C(2) bond lengths are 2.04 Å. B(1) is bonded in a linear geometry to two equivalent C(2) atoms. Both B(1)-C(2) bond lengths are 1.44 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded to two equivalent Al(2) and three equivalent Al(1) atoms to form corner-sharing CAl5 trigonal bipyramids. In the second C site, C(2) is bonded in a 5-coordinate geometry to one Al(1), three equivalent Al(2), and one B(1) atom.