Materials Data on Nb3AlCo8 by Materials Project

Abstract

Nb3Co8Al is Hexagonal Laves-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are three inequivalent Nb sites. In the first Nb site, Nb is bonded in a 12-coordinate geometry to four Nb and twelve Co atoms. There are one shorter (2.90 Å) and three longer (2.95 Å) Nb–Nb bond lengths. There are a spread of Nb–Co bond distances ranging from 2.75–2.82 Å. In the second Nb site, Nb is bonded in a 12-coordinate geometry to three equivalent Nb, twelve Co, and one Al atom. There are a spread of Nb–Co bond distances ranging from 2.74–2.85 Å. The Nb–Al bond length is 2.85 Å. In the third Nb site, Nb is bonded in a 12-coordinate geometry to one Nb, twelve Co, and three equivalent Al atoms. There are a spread of Nb–Co bond distances ranging from 2.74–2.81 Å. All Nb–Al bond lengths are 2.88 Å. There are four inequivalent Co sites. In the first Co site, Co is bonded to four Nb, six Co, and two equivalent Al atoms to form a mixture of corner, edge, and face-sharing CoNb4Al2Co6 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 Nb, six Co, and one Al atom to form a mixture of corner, edge, and face-sharing CoNb5AlCo6 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.36–2.40 Å. The Co–Al bond length is 2.76 Å. In the third Co site, Co is bonded to three equivalent Nb, six Co, and three equivalent Al atoms to form CoNb3Al3Co6 cuboctahedra that share corners with eighteen CoNb4Al2Co6 cuboctahedra, edges with six equivalent CoNb3Al3Co6 cuboctahedra, and faces with eighteen CoNb4Al2Co6 cuboctahedra. All Co–Al bond lengths are 2.77 Å. In the fourth Co site, Co is bonded to six Nb and six Co atoms to form CoNb6Co6 cuboctahedra that share corners with eighteen CoNb4Al2Co6 cuboctahedra, edges with six equivalent CoNb6Co6 cuboctahedra, and faces with eighteen CoNb4Al2Co6 cuboctahedra. Al is bonded in a 12-coordinate geometry to four Nb and twelve Co atoms.