Materials Data on Ta3AlCo8 by Materials Project

Abstract

Ta3Co8Al is Hexagonal Laves-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are three inequivalent Ta sites. In the first Ta site, Ta is bonded in a 12-coordinate geometry to four Ta and twelve Co atoms. There are one shorter (2.90 Å) and three longer (2.95 Å) Ta–Ta bond lengths. There are a spread of Ta–Co bond distances ranging from 2.76–2.81 Å. In the second Ta site, Ta is bonded in a 12-coordinate geometry to three equivalent Ta, twelve Co, and one Al atom. There are a spread of Ta–Co bond distances ranging from 2.75–2.83 Å. The Ta–Al bond length is 2.85 Å. In the third Ta site, Ta is bonded in a 12-coordinate geometry to one Ta, twelve Co, and three equivalent Al atoms. There are a spread of Ta–Co bond distances ranging from 2.75–2.81 Å. All Ta–Al bond lengths are 2.89 Å. There are four inequivalent Co sites. In the first Co site, Co is bonded to four Ta, six Co, and two equivalent Al atoms to form a mixture of face, edge, and corner-sharing CoTa4Al2Co6 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.35–2.39 Å. Both Co–Al bond lengths are 2.79 Å. In the second Co site, Co is bonded to five Ta, six Co, and one Al atom to form a mixture of face, edge, and corner-sharing CoTa5AlCo6 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.35–2.40 Å. The Co–Al bond length is 2.77 Å. In the third Co site, Co is bonded to three equivalent Ta, six Co, and three equivalent Al atoms to form CoTa3Al3Co6 cuboctahedra that share corners with eighteen CoTa4Al2Co6 cuboctahedra, edges with six equivalent CoTa3Al3Co6 cuboctahedra, and faces with eighteen CoTa4Al2Co6 cuboctahedra. All Co–Al bond lengths are 2.78 Å. In the fourth Co site, Co is bonded to six Ta and six Co atoms to form CoTa6Co6 cuboctahedra that share corners with eighteen CoTa4Al2Co6 cuboctahedra, edges with six equivalent CoTa6Co6 cuboctahedra, and faces with eighteen CoTa4Al2Co6 cuboctahedra. Al is bonded in a 12-coordinate geometry to four Ta and twelve Co atoms.