Materials Data on Ti5Al2C3 by Materials Project

Ti5Al2C3 is H-Phase-like structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are five inequivalent Ti sites. In the first Ti site, Ti is bonded to six C atoms to form edge-sharing TiC6 octahedra. There are three shorter (2.19 Å) and three longer (2.20 Å) Ti–C bond lengths. In the second Ti site, Ti is bonded in a 3-coordinate geometry to three equivalent Al and three equivalent C atoms. All Ti–Al bond lengths are 2.92 Å. All Ti–C bond lengths are 2.07 Å. In the third Ti site, Ti is bonded in a 3-coordinate geometry to three equivalent Al and three equivalent C atoms. All Ti–Al bond lengths are 2.90 Å. All Ti–C bond lengths are 2.11 Å. In the fourth Ti site, Ti is bonded in a 3-coordinate geometry to three equivalent Al and three equivalent C atoms. All Ti–Al bond lengths are 2.89 Å. All Ti–C bond lengths are 2.11 Å. In the fifth Ti site, Ti is bonded in a 3-coordinate geometry to three equivalent Al and three equivalent C atoms. All Ti–Al bond lengths are 2.91 Å. All Ti–C bond lengths are 2.07 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to six Ti and six equivalent Al atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent AlTi6Al6 cuboctahedra, corners with six CTi6 octahedra, edges with six equivalent AlTi6Al6 cuboctahedra, edges with six CTi6 octahedra, and faces with six equivalent AlTi6Al6 cuboctahedra. The corner-sharing octahedra tilt angles range from 19–21°. All Al–Al bond lengths are 3.07 Å. In the second Al site, Al is bonded to six Ti and six equivalent Al atoms to form distorted AlTi6Al6 cuboctahedra that share corners with six equivalent AlTi6Al6 cuboctahedra, corners with six CTi6 octahedra, edges with six equivalent AlTi6Al6 cuboctahedra, edges with six CTi6 octahedra, and faces with six equivalent AlTi6Al6 cuboctahedra. The corner-sharing octahedra tilt angles range from 19–21°. All Al–Al bond lengths are 3.07 Å. There are three inequivalent C sites. In the first C site, C is bonded to six Ti atoms to form CTi6 octahedra that share corners with three equivalent AlTi6Al6 cuboctahedra, corners with three equivalent CTi6 octahedra, edges with three equivalent AlTi6Al6 cuboctahedra, and edges with nine CTi6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second C site, C is bonded to six Ti atoms to form CTi6 octahedra that share corners with three equivalent AlTi6Al6 cuboctahedra, corners with three equivalent CTi6 octahedra, edges with three equivalent AlTi6Al6 cuboctahedra, and edges with nine CTi6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third C site, C is bonded to six Ti atoms to form CTi6 octahedra that share corners with six AlTi6Al6 cuboctahedra, edges with six AlTi6Al6 cuboctahedra, and edges with six equivalent CTi6 octahedra.