DOI: 10.17188/1274935
title: Materials Data on Al7(CN)3 by Materials Project

description: Al7C3N3 is Aluminum carbonitride-like structured and crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are seven inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to one C4- and three equivalent N3- atoms to form AlCN3 tetrahedra that share corners with twelve AlCN3 tetrahedra and a cornercorner with one AlC4 trigonal pyramid. The Al–C bond length is 1.93 Å. All Al–N bond lengths are 2.01 Å. In the second Al3+ site, Al3+ is bonded to four N3- atoms to form corner-sharing AlN4 tetrahedra. There is one shorter (1.85 Å) and three longer (1.99 Å) Al–N bond length. In the third Al3+ site, Al3+ is bonded to four C4- atoms to form distorted AlC4 tetrahedra that share corners with ten AlCN3 tetrahedra and edges with three equivalent AlC4 trigonal pyramids. There are three shorter (1.92 Å) and one longer (2.19 Å) Al–C bond lengths. In the fourth Al3+ site, Al3+ is bonded to three equivalent C4- and one N3- atom to form distorted AlC3N tetrahedra that share corners with twelve AlN4 tetrahedra and edges with three equivalent AlC3N tetrahedra. All Al–C bond lengths are 2.11 Å. The Al–N bond length is 1.85 Å. In the fifth Al3+ site, Al3+ is bonded to four C4- atoms to form distorted AlC4 trigonal pyramids that share corners with four AlCN3 tetrahedra, corners with six equivalent AlC4 trigonal pyramids, and edges with three equivalent AlC4 tetrahedra. There are three shorter (1.91 Å) and one longer (2.25 Å) Al–C bond lengths. In the sixth Al3+ site, Al3+ is bonded to three equivalent C4- and one N3- atom to form distorted AlC3N tetrahedra that share corners with twelve AlCN3 tetrahedra and edges with three equivalent AlC3N tetrahedra. All Al–C bond lengths are 2.14 Å. The Al–N bond length is 1.82 Å. In the seventh Al3+ site, Al3+ is bonded to one C4- and three equivalent N3- atoms to form AlCN3 tetrahedra that share corners with ten AlN4 tetrahedra and corners with three equivalent AlC4 trigonal pyramids. The Al–C bond length is 1.96 Å. There is two shorter (1.99 Å) and one longer (2.00 Å) Al–N bond length. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded to five Al3+ atoms to form distorted CAl5 trigonal bipyramids that share corners with three equivalent NAl4 tetrahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. In the second C4- site, C4- is bonded to five Al3+ atoms to form distorted CAl5 trigonal bipyramids that share corners with three equivalent NAl4 tetrahedra, corners with six equivalent CAl5 trigonal bipyramids, and edges with three equivalent CAl5 trigonal bipyramids. In the third C4- site, C4- is bonded to six Al3+ atoms to form CAl6 octahedra that share corners with six NAl4 tetrahedra and edges with six equivalent CAl6 octahedra. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded to four Al3+ atoms to form NAl4 tetrahedra that share corners with three equivalent CAl6 octahedra and corners with nine NAl4 tetrahedra. The corner-sharing octahedral tilt angles are 63°. In the second N3- site, N3- is bonded to four Al3+ atoms to form NAl4 tetrahedra that share corners with nine NAl4 tetrahedra and corners with three equivalent CAl5 trigonal bipyramids. In the third N3- site, N3- is bonded to four Al3+ atoms to form NAl4 tetrahedra that share corners with three equivalent CAl6 octahedra, corners with six equivalent NAl4 tetrahedra, and corners with three equivalent CAl5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 61°.