Materials Data on Y(Al2Cr)4 by Materials Project

Abstract

Al8Cr4Y crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Y is bonded in a 12-coordinate geometry to eight equivalent Cr and twelve Al atoms. All Y–Cr bond lengths are 3.40 Å. There are four shorter (3.01 Å) and eight longer (3.21 Å) Y–Al bond lengths. Cr is bonded to two equivalent Y, two equivalent Cr, and eight Al atoms to form distorted CrY2Al8Cr2 cuboctahedra that share corners with eight equivalent AlY2Al6Cr4 cuboctahedra, corners with ten equivalent CrY2Al8Cr2 cuboctahedra, edges with four equivalent CrY2Al8Cr2 cuboctahedra, edges with four equivalent AlY2Al6Cr4 cuboctahedra, faces with six equivalent CrY2Al8Cr2 cuboctahedra, and faces with eight equivalent AlY2Al6Cr4 cuboctahedra. Both Cr–Cr bond lengths are 2.53 Å. There are four shorter (2.57 Å) and four longer (2.68 Å) Cr–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to one Y, four equivalent Cr, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.72–2.91 Å. In the second Al site, Al is bonded to two equivalent Y, four equivalent Cr, and six Al atoms to form distorted AlY2Al6Cr4 cuboctahedra that share corners with eight equivalent CrY2Al8Cr2 cuboctahedra, corners with ten equivalent AlY2Al6Cr4 cuboctahedra, edges with three equivalent AlY2Al6Cr4 cuboctahedra, edges with four equivalent CrY2Al8Cr2 cuboctahedra, faces with seven equivalent AlY2Al6Cr4 cuboctahedra, and faces with eight equivalent CrY2Al8Cr2 cuboctahedra. Both Al–Al bond lengths are 2.81 Å.