Al5C3N is Aluminum carbonitride structured and crystallizes in the hexagonal P6_3mc space group. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded to one C(1) and three equivalent N(1) atoms to form AlCN3 tetrahedra that share  a cornercorner with one Al(5)C4 tetrahedra, corners with three equivalent Al(2)C3N tetrahedra, corners with six equivalent Al(1)CN3 tetrahedra, and corners with three equivalent Al(3)C4 trigonal pyramids. In the second Al site, Al(2) is bonded to three equivalent C(3) and one N(1) atom to form distorted AlC3N tetrahedra that share corners with three equivalent Al(4)C4 tetrahedra, corners with three equivalent Al(1)CN3 tetrahedra, corners with six equivalent Al(2)C3N tetrahedra, and edges with three equivalent Al(4)C4 tetrahedra. In the third Al site, Al(3) is bonded to one C(2) and three equivalent C(1) atoms to form distorted AlC4 trigonal pyramids that share  a cornercorner with one Al(4)C4 tetrahedra, corners with three equivalent Al(1)CN3 tetrahedra, corners with six equivalent Al(3)C4 trigonal pyramids, and edges with three equivalent Al(5)C4 tetrahedra. In the fourth Al site, Al(4) is bonded to one C(2) and three equivalent C(3) atoms to form distorted AlC4 tetrahedra that share corners with three equivalent Al(2)C3N tetrahedra, corners with three equivalent Al(5)C4 tetrahedra, corners with six equivalent Al(4)C4 tetrahedra,  a cornercorner with one Al(3)C4 trigonal pyramid, and edges with three equivalent Al(2)C3N tetrahedra. In the fifth Al site, Al(5) is bonded to one C(1) and three equivalent C(2) atoms to form distorted AlC4 tetrahedra that share  a cornercorner with one Al(1)CN3 tetrahedra, corners with three equivalent Al(4)C4 tetrahedra, corners with six equivalent Al(5)C4 tetrahedra, and edges with three equivalent Al(3)C4 trigonal pyramids. There are three inequivalent C sites. In the first C site, C(1) is bonded to one Al(1), one Al(5), and three equivalent Al(3) atoms to form CAl5 trigonal bipyramids that share corners with three equivalent N(1)Al4 tetrahedra, corners with six equivalent C(1)Al5 trigonal bipyramids, and edges with three equivalent C(2)Al5 trigonal bipyramids. In the second C site, C(2) is bonded to one Al(3), one Al(4), and three equivalent Al(5) atoms to form distorted CAl5 trigonal bipyramids that share corners with three equivalent C(3)Al6 octahedra, corners with six equivalent C(2)Al5 trigonal bipyramids, and edges with three equivalent C(1)Al5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 61°. In the third C site, C(3) is bonded to three equivalent Al(2) and three equivalent Al(4) atoms to form CAl6 octahedra that share corners with three equivalent N(1)Al4 tetrahedra, corners with three equivalent C(2)Al5 trigonal bipyramids, and edges with six equivalent C(3)Al6 octahedra. N(1) is bonded to one Al(2) and three equivalent Al(1) atoms to form NAl4 tetrahedra that share corners with three equivalent C(3)Al6 octahedra, corners with six equivalent N(1)Al4 tetrahedra, and corners with three equivalent C(1)Al5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 64°.
Al5C3N is Aluminum carbonitride structured and crystallizes in the hexagonal P6_3mc space group. There are five inequivalent Al sites. In the first Al site, Al(1) is bonded to one C(1) and three equivalent N(1) atoms to form AlCN3 tetrahedra that share  a cornercorner with one Al(5)C4 tetrahedra, corners with three equivalent Al(2)C3N tetrahedra, corners with six equivalent Al(1)CN3 tetrahedra, and corners with three equivalent Al(3)C4 trigonal pyramids. The Al(1)-C(1) bond length is 1.96 Å. All Al(1)-N(1) bond lengths are 2.02 Å. In the second Al site, Al(2) is bonded to three equivalent C(3) and one N(1) atom to form distorted AlC3N tetrahedra that share corners with three equivalent Al(4)C4 tetrahedra, corners with three equivalent Al(1)CN3 tetrahedra, corners with six equivalent Al(2)C3N tetrahedra, and edges with three equivalent Al(4)C4 tetrahedra. All Al(2)-C(3) bond lengths are 2.12 Å. The Al(2)-N(1) bond length is 1.85 Å. In the third Al site, Al(3) is bonded to one C(2) and three equivalent C(1) atoms to form distorted AlC4 trigonal pyramids that share  a cornercorner with one Al(4)C4 tetrahedra, corners with three equivalent Al(1)CN3 tetrahedra, corners with six equivalent Al(3)C4 trigonal pyramids, and edges with three equivalent Al(5)C4 tetrahedra. The Al(3)-C(2) bond length is 2.26 Å. All Al(3)-C(1) bond lengths are 1.93 Å. In the fourth Al site, Al(4) is bonded to one C(2) and three equivalent C(3) atoms to form distorted AlC4 tetrahedra that share corners with three equivalent Al(2)C3N tetrahedra, corners with three equivalent Al(5)C4 tetrahedra, corners with six equivalent Al(4)C4 tetrahedra,  a cornercorner with one Al(3)C4 trigonal pyramid, and edges with three equivalent Al(2)C3N tetrahedra. The Al(4)-C(2) bond length is 1.90 Å. All Al(4)-C(3) bond lengths are 2.19 Å. In the fifth Al site, Al(5) is bonded to one C(1) and three equivalent C(2) atoms to form distorted AlC4 tetrahedra that share  a cornercorner with one Al(1)CN3 tetrahedra, corners with three equivalent Al(4)C4 tetrahedra, corners with six equivalent Al(5)C4 tetrahedra, and edges with three equivalent Al(3)C4 trigonal pyramids. The Al(5)-C(1) bond length is 2.15 Å. All Al(5)-C(2) bond lengths are 1.95 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded to one Al(1), one Al(5), and three equivalent Al(3) atoms to form CAl5 trigonal bipyramids that share corners with three equivalent N(1)Al4 tetrahedra, corners with six equivalent C(1)Al5 trigonal bipyramids, and edges with three equivalent C(2)Al5 trigonal bipyramids. In the second C site, C(2) is bonded to one Al(3), one Al(4), and three equivalent Al(5) atoms to form distorted CAl5 trigonal bipyramids that share corners with three equivalent C(3)Al6 octahedra, corners with six equivalent C(2)Al5 trigonal bipyramids, and edges with three equivalent C(1)Al5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 61°. In the third C site, C(3) is bonded to three equivalent Al(2) and three equivalent Al(4) atoms to form CAl6 octahedra that share corners with three equivalent N(1)Al4 tetrahedra, corners with three equivalent C(2)Al5 trigonal bipyramids, and edges with six equivalent C(3)Al6 octahedra. N(1) is bonded to one Al(2) and three equivalent Al(1) atoms to form NAl4 tetrahedra that share corners with three equivalent C(3)Al6 octahedra, corners with six equivalent N(1)Al4 tetrahedra, and corners with three equivalent C(1)Al5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 64°.