Materials Data on U(Al10Cr)2 by Materials Project

Abstract

U(CrAl10)2 crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. U is bonded in a 4-coordinate geometry to sixteen Al atoms. There are four shorter (3.11 Å) and twelve longer (3.17 Å) U–Al bond lengths. Cr is bonded to twelve Al atoms to form CrAl12 cuboctahedra that share corners with six equivalent CrAl12 cuboctahedra, edges with eighteen equivalent AlUAl10Cr cuboctahedra, and faces with six equivalent AlUAl10Cr cuboctahedra. There are six shorter (2.54 Å) and six longer (2.78 Å) Cr–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded in a distorted linear geometry to two equivalent U and twelve equivalent Al atoms. All Al–Al bond lengths are 3.07 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.70–2.82 Å. In the third Al site, Al is bonded to one U, one Cr, and ten Al atoms to form distorted AlUAl10Cr cuboctahedra that share corners with fifteen equivalent AlUAl10Cr cuboctahedra, edges with two equivalent AlUAl10Cr cuboctahedra, edges with three equivalent CrAl12 cuboctahedra, a faceface with one CrAl12 cuboctahedra, and faces with fifteen equivalent AlUAl10Cr cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.68–2.90 Å.