Materials Data on Be17Nb2 by Materials Project
Be17Nb2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are four inequivalent Be sites. In the first Be site, Be is bonded in a 1-coordinate geometry to thirteen Be and one Nb atom. There are a spread of Be–Be bond distances ranging from 2.12–2.41 Å. The Be–Nb bond length is 2.60 Å. In the second Be site, Be is bonded in a 12-coordinate geometry to ten Be and two equivalent Nb atoms. There are four shorter (2.11 Å) and four longer (2.15 Å) Be–Be bond lengths. Both Be–Nb bond lengths are 2.84 Å. In the third Be site, Be is bonded to ten Be and two equivalent Nb atoms to form distorted BeBe10Nb2 cuboctahedra that share corners with twenty BeBe9Nb3 cuboctahedra, edges with three BeBe9Nb3 cuboctahedra, and faces with seventeen BeBe10Nb2 cuboctahedra. There are a spread of Be–Be bond distances ranging from 2.17–2.26 Å. Both Be–Nb bond lengths are 2.62 Å. In the fourth Be site, Be is bonded to nine Be and three equivalent Nb atoms to form distorted BeBe9Nb3 cuboctahedra that share corners with eighteen BeBe9Nb3 cuboctahedra, edges with seven BeBe9Nb3 cuboctahedra, and faces with seventeen BeBe10Nb2 cuboctahedra. Both Be–Be bond lengths are 2.11 Å. There are one shorter (2.63 Å) and two longer (2.78 Å) Be–Nb bond lengths. Nb is bonded in a 10-coordinate geometry to nineteen Be atoms.