DOI: 10.17188/1746713
title: Materials Data on AlCo4 by Materials Project

description: Co4Al crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Co sites. In the first Co site, Co is bonded to nine Co and three equivalent Al atoms to form distorted CoAl3Co9 cuboctahedra that share corners with twelve CoAl3Co9 cuboctahedra, edges with six equivalent AlAl6Co6 cuboctahedra, edges with eighteen CoAl3Co9 cuboctahedra, faces with six equivalent AlAl6Co6 cuboctahedra, and faces with twelve CoAl3Co9 cuboctahedra. There are three shorter (2.45 Å) and six longer (2.58 Å) Co–Co bond lengths. All Co–Al bond lengths are 2.52 Å. In the second Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with three equivalent AlAl6Co6 cuboctahedra, corners with nine CoAl3Co9 cuboctahedra, edges with three equivalent AlAl6Co6 cuboctahedra, edges with twenty-one CoAl3Co9 cuboctahedra, and faces with eighteen CoAl3Co9 cuboctahedra. There are three shorter (2.50 Å) and six longer (2.58 Å) Co–Co bond lengths. In the third Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with three equivalent AlAl6Co6 cuboctahedra, corners with nine CoAl3Co9 cuboctahedra, edges with three equivalent AlAl6Co6 cuboctahedra, edges with twenty-one CoAl3Co9 cuboctahedra, and faces with eighteen CoAl3Co9 cuboctahedra. There are three shorter (2.45 Å) and six longer (2.58 Å) Co–Co bond lengths. In the fourth Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with three equivalent AlAl6Co6 cuboctahedra, corners with nine CoCo12 cuboctahedra, edges with three equivalent AlAl6Co6 cuboctahedra, edges with twenty-one CoCo12 cuboctahedra, and faces with eighteen CoCo12 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.45–2.58 Å. In the fifth Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with three equivalent AlAl6Co6 cuboctahedra, corners with nine CoCo12 cuboctahedra, edges with three equivalent AlAl6Co6 cuboctahedra, edges with twenty-one CoCo12 cuboctahedra, and faces with eighteen CoCo12 cuboctahedra. There are three shorter (2.45 Å) and six longer (2.58 Å) Co–Co bond lengths. In the sixth Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with three equivalent AlAl6Co6 cuboctahedra, corners with nine CoAl3Co9 cuboctahedra, edges with three equivalent AlAl6Co6 cuboctahedra, edges with twenty-one CoAl3Co9 cuboctahedra, and faces with eighteen CoAl3Co9 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.45–2.58 Å. In the seventh Co site, Co is bonded to twelve Co atoms to form CoCo12 cuboctahedra that share corners with three equivalent AlAl6Co6 cuboctahedra, corners with nine CoAl3Co9 cuboctahedra, edges with three equivalent AlAl6Co6 cuboctahedra, edges with twenty-one CoAl3Co9 cuboctahedra, and faces with eighteen CoAl3Co9 cuboctahedra. There are three shorter (2.45 Å) and six longer (2.58 Å) Co–Co bond lengths. Al is bonded to six equivalent Co and six equivalent Al atoms to form distorted AlAl6Co6 cuboctahedra that share corners with six CoCo12 cuboctahedra, corners with six equivalent AlAl6Co6 cuboctahedra, edges with six equivalent AlAl6Co6 cuboctahedra, edges with eighteen CoCo12 cuboctahedra, faces with six equivalent AlAl6Co6 cuboctahedra, and faces with twelve equivalent CoAl3Co9 cuboctahedra. All Al–Al bond lengths are 2.58 Å.