Ti4AlN3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to three equivalent N(1) and three equivalent N(2) atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedra are not tilted. In the second Ti site, Ti(2) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent N(1) atoms. Al(1) is bonded to six equivalent Ti(2) and six equivalent Al(1) atoms to form AlTi6Al6 cuboctahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, corners with six equivalent N(1)Ti6 octahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with six equivalent N(1)Ti6 octahedra, and faces with six equivalent Al(1)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Ti(1) and three equivalent Ti(2) atoms to form NTi6 octahedra that share corners with three equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent N(2)Ti6 octahedra, edges with three equivalent Al(1)Ti6Al6 cuboctahedra, edges with three equivalent N(2)Ti6 octahedra, and edges with six equivalent N(1)Ti6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second N site, N(2) is bonded to six equivalent Ti(1) atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedral tilt angles are 1°.
Ti4AlN3 is MAX Phase structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to three equivalent N(1) and three equivalent N(2) atoms to form a mixture of edge and corner-sharing TiN6 octahedra. The corner-sharing octahedra are not tilted. All Ti(1)-N(1) bond lengths are 2.10 Å. All Ti(1)-N(2) bond lengths are 2.14 Å. In the second Ti site, Ti(2) is bonded in a 3-coordinate geometry to three equivalent Al(1) and three equivalent N(1) atoms. All Ti(2)-Al(1) bond lengths are 2.82 Å. All Ti(2)-N(1) bond lengths are 2.07 Å. Al(1) is bonded to six equivalent Ti(2) and six equivalent Al(1) atoms to form AlTi6Al6 cuboctahedra that share corners with six equivalent Al(1)Ti6Al6 cuboctahedra, corners with six equivalent N(1)Ti6 octahedra, edges with six equivalent Al(1)Ti6Al6 cuboctahedra, edges with six equivalent N(1)Ti6 octahedra, and faces with six equivalent Al(1)Ti6Al6 cuboctahedra. The corner-sharing octahedral tilt angles are 19°. All Al(1)-Al(1) bond lengths are 2.98 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded to three equivalent Ti(1) and three equivalent Ti(2) atoms to form NTi6 octahedra that share corners with three equivalent Al(1)Ti6Al6 cuboctahedra, corners with three equivalent N(2)Ti6 octahedra, edges with three equivalent Al(1)Ti6Al6 cuboctahedra, edges with three equivalent N(2)Ti6 octahedra, and edges with six equivalent N(1)Ti6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the second N site, N(2) is bonded to six equivalent Ti(1) atoms to form a mixture of edge and corner-sharing NTi6 octahedra. The corner-sharing octahedral tilt angles are 1°.