Materials Data on HoAl3 by Materials Project

Abstract

HoAl3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Ho sites. In the first Ho site, Ho is bonded to twelve Al atoms to form HoAl12 cuboctahedra that share corners with six equivalent HoAl12 cuboctahedra, edges with six equivalent AlHo4Al8 cuboctahedra, faces with six equivalent AlHo4Al8 cuboctahedra, and faces with eight equivalent HoAl12 cuboctahedra. There are six shorter (3.06 Å) and six longer (3.08 Å) Ho–Al bond lengths. In the second Ho site, Ho is bonded to twelve Al atoms to form HoAl12 cuboctahedra that share corners with six equivalent AlHo4Al8 cuboctahedra, corners with nine equivalent HoAl12 cuboctahedra, edges with six equivalent AlHo4Al8 cuboctahedra, faces with three equivalent AlHo4Al8 cuboctahedra, and faces with seven HoAl12 cuboctahedra. There are a spread of Ho–Al bond distances ranging from 3.02–3.09 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to four Ho and six Al atoms. There are a spread of Al–Al bond distances ranging from 2.73–2.88 Å. In the second Al site, Al is bonded to four Ho and eight Al atoms to form distorted AlHo4Al8 cuboctahedra that share corners with four equivalent HoAl12 cuboctahedra, corners with six equivalent AlHo4Al8 cuboctahedra, edges with four equivalent AlHo4Al8 cuboctahedra, edges with six HoAl12 cuboctahedra, faces with four HoAl12 cuboctahedra, and faces with four equivalent AlHo4Al8 cuboctahedra. All Al–Al bond lengths are 3.08 Å.