Materials Data on Al8Cr5 by Materials Project

Abstract

Al8Cr5 is Bergman Structure: Mg32(Al,Zn)49 Bergman-derived structured and crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are four inequivalent Cr sites. In the first Cr site, Cr is bonded in a 12-coordinate geometry to nine Cr and three equivalent Al atoms. There are a spread of Cr–Cr bond distances ranging from 2.30–2.71 Å. All Cr–Al bond lengths are 2.61 Å. In the second Cr site, Cr is bonded in a 12-coordinate geometry to six Cr and six Al atoms. There are three shorter (2.58 Å) and two longer (2.81 Å) Cr–Cr bond lengths. There are a spread of Cr–Al bond distances ranging from 2.51–2.72 Å. In the third Cr site, Cr is bonded in a 12-coordinate geometry to five Cr and seven Al atoms. Both Cr–Cr bond lengths are 2.82 Å. There are a spread of Cr–Al bond distances ranging from 2.55–2.64 Å. In the fourth Cr site, Cr is bonded in a 12-coordinate geometry to four Cr and eight Al atoms. There are a spread of Cr–Al bond distances ranging from 2.60–2.88 Å. There are five inequivalent Al sites. In the first Al site, Al is bonded in a distorted cuboctahedral geometry to three equivalent Cr and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.68–2.77 Å. In the second Al site, Al is bonded in a 1-coordinate geometry to four Cr and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.62–3.04 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to four Cr and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–2.86 Å. In the fourth Al site, Al is bonded in a 11-coordinate geometry to three Cr and eight Al atoms. Both Al–Al bond lengths are 2.92 Å. In the fifth Al site, Al is bonded in a 12-coordinate geometry to five Cr and six Al atoms. Both Al–Al bond lengths are 2.79 Å.