Materials Data on Tm(AlCr)6 by Materials Project

Abstract

Tm(CrAl)6 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Tm is bonded in a 8-coordinate geometry to twelve Cr and eight Al atoms. There are four shorter (3.29 Å) and eight longer (3.34 Å) Tm–Cr bond lengths. There are a spread of Tm–Al bond distances ranging from 2.93–3.03 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded to two equivalent Tm, four Cr, and six Al atoms to form a mixture of distorted corner, edge, and face-sharing CrTm2Al6Cr4 cuboctahedra. There are two shorter (2.51 Å) and two longer (2.53 Å) Cr–Cr bond lengths. There are a spread of Cr–Al bond distances ranging from 2.59–2.67 Å. In the second Cr site, Cr is bonded to two equivalent Tm, four equivalent Cr, and six Al atoms to form a mixture of distorted corner, edge, and face-sharing CrTm2Al6Cr4 cuboctahedra. There are a spread of Cr–Al bond distances ranging from 2.65–2.69 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Tm, six Cr, and three Al atoms. There are one shorter (2.68 Å) and two longer (2.85 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 8-coordinate geometry to one Tm, six Cr, and two equivalent Al atoms. Both Al–Al bond lengths are 3.05 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Tm, six Cr, and four Al atoms.