DOI: 10.17188/1750149
title: Materials Data on Ti5Al11 by Materials Project

description: Ti5Al11 is beta Cu3Ti-like structured and crystallizes in the tetragonal P4mm space group. The structure is three-dimensional. there are five inequivalent Ti sites. In the first Ti site, Ti is bonded to twelve Al atoms to form TiAl12 cuboctahedra that share corners with twelve TiAl12 cuboctahedra, edges with four equivalent TiTi4Al8 cuboctahedra, edges with twenty AlTi6Al6 cuboctahedra, faces with six TiAl12 cuboctahedra, and faces with twelve AlTi4Al8 cuboctahedra. There are a spread of Ti–Al bond distances ranging from 2.77–2.86 Å. In the second Ti site, Ti is bonded to twelve Al atoms to form TiAl12 cuboctahedra that share corners with four equivalent AlTi4Al8 cuboctahedra, corners with eight TiAl12 cuboctahedra, edges with eight TiAl12 cuboctahedra, edges with sixteen AlTi4Al8 cuboctahedra, faces with five TiAl12 cuboctahedra, and faces with thirteen AlTi6Al6 cuboctahedra. There are a spread of Ti–Al bond distances ranging from 2.77–2.90 Å. In the third Ti site, Ti is bonded to four equivalent Ti and eight Al atoms to form TiTi4Al8 cuboctahedra that share corners with four equivalent AlTi4Al8 cuboctahedra, corners with eight TiAl12 cuboctahedra, edges with four equivalent TiAl12 cuboctahedra, edges with twenty AlTi6Al6 cuboctahedra, faces with nine TiAl12 cuboctahedra, and faces with nine AlTi6Al6 cuboctahedra. All Ti–Ti bond lengths are 2.79 Å. There are four shorter (2.74 Å) and four longer (2.92 Å) Ti–Al bond lengths. In the fourth Ti site, Ti is bonded to twelve Al atoms to form TiAl12 cuboctahedra that share corners with four equivalent AlTi4Al8 cuboctahedra, corners with eight TiAl12 cuboctahedra, edges with four equivalent TiAl12 cuboctahedra, edges with twenty AlTi4Al8 cuboctahedra, faces with five TiAl12 cuboctahedra, and faces with thirteen AlTi4Al8 cuboctahedra. There are a spread of Ti–Al bond distances ranging from 2.76–2.93 Å. In the fifth Ti site, Ti is bonded to four equivalent Ti and eight Al atoms to form TiTi4Al8 cuboctahedra that share corners with four equivalent AlTi4Al8 cuboctahedra, corners with eight TiAl12 cuboctahedra, edges with four equivalent TiAl12 cuboctahedra, edges with twenty AlTi6Al6 cuboctahedra, faces with nine TiAl12 cuboctahedra, and faces with nine AlTi6Al6 cuboctahedra. There are four shorter (2.73 Å) and four longer (2.94 Å) Ti–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded to six Ti and six Al atoms to form AlTi6Al6 cuboctahedra that share corners with twelve AlTi6Al6 cuboctahedra, edges with twelve TiAl12 cuboctahedra, edges with twelve AlTi6Al6 cuboctahedra, faces with six TiAl12 cuboctahedra, and faces with twelve AlTi6Al6 cuboctahedra. There are four shorter (2.77 Å) and two longer (2.85 Å) Al–Al bond lengths. In the second Al site, Al is bonded to four Ti and eight Al atoms to form AlTi4Al8 cuboctahedra that share corners with twelve AlTi6Al6 cuboctahedra, edges with eight TiAl12 cuboctahedra, edges with sixteen AlTi6Al6 cuboctahedra, faces with four TiAl12 cuboctahedra, and faces with fourteen AlTi4Al8 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.77–2.86 Å. In the third Al site, Al is bonded to six Ti and six Al atoms to form AlTi6Al6 cuboctahedra that share corners with twelve AlTi6Al6 cuboctahedra, edges with twelve TiAl12 cuboctahedra, edges with twelve AlTi6Al6 cuboctahedra, faces with six TiAl12 cuboctahedra, and faces with twelve AlTi6Al6 cuboctahedra. There are four shorter (2.77 Å) and two longer (2.84 Å) Al–Al bond lengths. In the fourth Al site, Al is bonded to four Ti and eight Al atoms to form AlTi4Al8 cuboctahedra that share corners with twelve AlTi4Al8 cuboctahedra, edges with eight TiAl12 cuboctahedra, edges with sixteen AlTi6Al6 cuboctahedra, faces with four TiAl12 cuboctahedra, and faces with fourteen AlTi6Al6 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.77–2.85 Å. In the fifth Al site, Al is bonded to four equivalent Ti and eight Al atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent TiAl12 cuboctahedra, corners with eight AlTi4Al8 cuboctahedra, edges with four equivalent TiAl12 cuboctahedra, edges with twenty AlTi4Al8 cuboctahedra, faces with five TiAl12 cuboctahedra, and faces with thirteen AlTi4Al8 cuboctahedra. In the sixth Al site, Al is bonded to four equivalent Ti and eight Al atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent TiTi4Al8 cuboctahedra, corners with eight AlTi4Al8 cuboctahedra, edges with eight TiAl12 cuboctahedra, edges with sixteen AlTi6Al6 cuboctahedra, faces with five TiAl12 cuboctahedra, and faces with thirteen AlTi4Al8 cuboctahedra. In the seventh Al site, Al is bonded to four equivalent Ti and eight Al atoms to form AlTi4Al8 cuboctahedra that share corners with four equivalent AlTi4Al8 cuboctahedra, corners with eight TiAl12 cuboctahedra, edges with four equivalent TiTi4Al8 cuboctahedra, edges with twenty AlTi4Al8 cuboctahedra, faces with six TiAl12 cuboctahedra, and faces with twelve AlTi6Al6 cuboctahedra.