Materials Data on Ta2Be17 by Materials Project
Be17Ta2 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 Ta atom. There are a spread of Be–Be bond distances ranging from 2.13–2.42 Å. The Be–Ta bond length is 2.59 Å. In the second Be site, Be is bonded to ten Be and two equivalent Ta atoms to form distorted BeTa2Be10 cuboctahedra that share corners with twenty-two BeTa2Be10 cuboctahedra, edges with ten BeTa3Be9 cuboctahedra, and faces with eighteen BeTa2Be10 cuboctahedra. There are four shorter (2.11 Å) and four longer (2.14 Å) Be–Be bond lengths. Both Be–Ta bond lengths are 2.83 Å. In the third Be site, Be is bonded to ten Be and two equivalent Ta atoms to form distorted BeTa2Be10 cuboctahedra that share corners with twenty-four BeTa2Be10 cuboctahedra, edges with five BeTa3Be9 cuboctahedra, and faces with twenty-one BeTa2Be10 cuboctahedra. There are a spread of Be–Be bond distances ranging from 2.17–2.26 Å. Both Be–Ta bond lengths are 2.60 Å. In the fourth Be site, Be is bonded to nine Be and three equivalent Ta atoms to form a mixture of distorted edge, face, and corner-sharing BeTa3Be9 cuboctahedra. Both Be–Be bond lengths are 2.10 Å. There are a spread of Be–Ta bond distances ranging from 2.63–2.78 Å. Ta is bonded in a 10-coordinate geometry to nineteen Be atoms.