Materials Data on Er6Al43Cr4 by Materials Project

Abstract

Er6Cr4Al43 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. Er is bonded in a 6-coordinate geometry to one Er, one Cr, and fifteen Al atoms. The Er–Er bond length is 3.38 Å. The Er–Cr bond length is 3.46 Å. There are a spread of Er–Al bond distances ranging from 3.02–3.44 Å. There are two inequivalent Cr sites. In the first Cr site, Cr is bonded in a 12-coordinate geometry to two equivalent Er and ten Al atoms. There are a spread of Cr–Al bond distances ranging from 2.55–2.65 Å. In the second Cr site, Cr is bonded to twelve Al atoms to form CrAl12 cuboctahedra that share edges with six equivalent AlAl10Cr2 cuboctahedra. There are six shorter (2.63 Å) and six longer (2.79 Å) Cr–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to one Er, two Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.69–2.92 Å. In the second Al site, Al is bonded in a 12-coordinate geometry to four equivalent Er and eight Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–3.06 Å. In the third Al site, Al is bonded in a 12-coordinate geometry to two equivalent Er, one Cr, and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.71–3.00 Å. In the fourth Al site, Al is bonded to two equivalent Cr and ten Al atoms to form distorted AlAl10Cr2 cuboctahedra that share corners with four equivalent AlEr3Al9 cuboctahedra, edges with two equivalent CrAl12 cuboctahedra, and faces with two equivalent AlAl10Cr2 cuboctahedra. Both Al–Al bond lengths are 2.74 Å. In the fifth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Er, one Cr, and nine Al atoms. Both Al–Al bond lengths are 2.94 Å. In the sixth Al site, Al is bonded to three equivalent Er and nine Al atoms to form a mixture of face and corner-sharing AlEr3Al9 cuboctahedra. All Al–Al bond lengths are 2.79 Å. In the seventh Al site, Al is bonded in a 10-coordinate geometry to two equivalent Er, one Cr, and seven Al atoms. The Al–Al bond length is 2.72 Å.