Al6C3N2 is Aluminum carbonitride-like structured and crystallizes in the trigonal R-3m space group. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent C(1) and one N(1) atom to form distorted AlC3N tetrahedra that share corners with three equivalent Al(2)CN3 tetrahedra, corners with nine equivalent Al(1)C3N tetrahedra, and edges with three equivalent Al(1)C3N tetrahedra. In the second Al site, Al(2) is bonded to one C(2) and three equivalent N(1) atoms to form AlCN3 tetrahedra that share corners with three equivalent Al(1)C3N tetrahedra, corners with four equivalent Al(3)C4 tetrahedra, and corners with six equivalent Al(2)CN3 tetrahedra. In the third Al site, Al(3) is bonded to four equivalent C(2) atoms to form distorted AlC4 tetrahedra that share corners with four equivalent Al(2)CN3 tetrahedra, corners with six equivalent Al(3)C4 tetrahedra, and edges with three equivalent Al(3)C4 tetrahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded to six equivalent Al(1) atoms to form CAl6 octahedra that share corners with six equivalent N(1)Al4 tetrahedra and edges with six equivalent C(1)Al6 octahedra. In the second C site, C(2) is bonded to one Al(2) and four equivalent Al(3) atoms to form distorted CAl5 trigonal bipyramids that share corners with three equivalent N(1)Al4 tetrahedra, corners with six equivalent C(2)Al5 trigonal bipyramids, and edges with three equivalent C(2)Al5 trigonal bipyramids. N(1) is bonded to one Al(1) and three equivalent Al(2) atoms to form NAl4 tetrahedra that share corners with three equivalent C(1)Al6 octahedra, corners with six equivalent N(1)Al4 tetrahedra, and corners with three equivalent C(2)Al5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°.
Al6C3N2 is Aluminum carbonitride-like structured and crystallizes in the trigonal R-3m space group. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent C(1) and one N(1) atom to form distorted AlC3N tetrahedra that share corners with three equivalent Al(2)CN3 tetrahedra, corners with nine equivalent Al(1)C3N tetrahedra, and edges with three equivalent Al(1)C3N tetrahedra. All Al(1)-C(1) bond lengths are 2.14 Å. The Al(1)-N(1) bond length is 1.80 Å. In the second Al site, Al(2) is bonded to one C(2) and three equivalent N(1) atoms to form AlCN3 tetrahedra that share corners with three equivalent Al(1)C3N tetrahedra, corners with four equivalent Al(3)C4 tetrahedra, and corners with six equivalent Al(2)CN3 tetrahedra. The Al(2)-C(2) bond length is 1.90 Å. All Al(2)-N(1) bond lengths are 2.03 Å. In the third Al site, Al(3) is bonded to four equivalent C(2) atoms to form distorted AlC4 tetrahedra that share corners with four equivalent Al(2)CN3 tetrahedra, corners with six equivalent Al(3)C4 tetrahedra, and edges with three equivalent Al(3)C4 tetrahedra. There are three shorter (1.93 Å) and one longer (2.21 Å) Al(3)-C(2) bond length. There are two inequivalent C sites. In the first C site, C(1) is bonded to six equivalent Al(1) atoms to form CAl6 octahedra that share corners with six equivalent N(1)Al4 tetrahedra and edges with six equivalent C(1)Al6 octahedra. In the second C site, C(2) is bonded to one Al(2) and four equivalent Al(3) atoms to form distorted CAl5 trigonal bipyramids that share corners with three equivalent N(1)Al4 tetrahedra, corners with six equivalent C(2)Al5 trigonal bipyramids, and edges with three equivalent C(2)Al5 trigonal bipyramids. N(1) is bonded to one Al(1) and three equivalent Al(2) atoms to form NAl4 tetrahedra that share corners with three equivalent C(1)Al6 octahedra, corners with six equivalent N(1)Al4 tetrahedra, and corners with three equivalent C(2)Al5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 62°.