DOI: 10.17188/1205351
title: Materials Data on Al45Cr7 by Materials Project

description: Al45Cr7 is Bergman Structure: Mg32(Al,Zn)49 Bergman-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Cr sites. In the first Cr site, Cr is bonded to twelve Al atoms to form corner-sharing CrAl12 cuboctahedra. There are a spread of Cr–Al bond distances ranging from 2.56–2.89 Å. In the second Cr site, Cr is bonded to twelve Al atoms to form distorted CrAl12 cuboctahedra that share a cornercorner with one CrAl12 cuboctahedra, a cornercorner with one AlAl8Cr4 cuboctahedra, and a faceface with one AlAl9Cr3 cuboctahedra. There are a spread of Cr–Al bond distances ranging from 2.47–2.91 Å. In the third Cr site, Cr is bonded in a 12-coordinate geometry to one Cr and eleven Al atoms. The Cr–Cr bond length is 2.64 Å. There are a spread of Cr–Al bond distances ranging from 2.47–2.79 Å. There are eighteen inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Cr and eight Al atoms to form AlAl8Cr4 cuboctahedra that share corners with two equivalent CrAl12 cuboctahedra and faces with two equivalent AlAl9Cr3 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.57–2.70 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 2.79–2.88 Å. In the third Al site, Al is bonded in a 11-coordinate geometry to three Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.66–3.03 Å. In the fourth Al site, Al is bonded to three Cr and nine Al atoms to form distorted AlAl9Cr3 cuboctahedra that share a cornercorner with one AlAl9Cr3 cuboctahedra, a faceface with one CrAl12 cuboctahedra, and a faceface with one AlAl8Cr4 cuboctahedra. There are a spread of Al–Al bond distances ranging from 2.73–2.84 Å. In the fifth Al site, Al is bonded in a 11-coordinate geometry to two equivalent Cr and nine Al atoms. There are a spread of Al–Al bond distances ranging from 2.73–2.84 Å. In the sixth Al site, Al is bonded in a 2-coordinate geometry to two equivalent Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–2.89 Å. In the seventh Al site, Al is bonded in a 12-coordinate geometry to two Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.68–2.92 Å. In the eighth Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.74–3.00 Å. In the ninth Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.66–2.92 Å. In the tenth Al site, Al is bonded in a 12-coordinate geometry to two Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.75–2.96 Å. In the eleventh Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.73–2.93 Å. In the twelfth Al site, Al is bonded in a 2-coordinate geometry to two Cr and ten Al atoms. There are one shorter (2.85 Å) and one longer (2.88 Å) Al–Al bond lengths. In the thirteenth Al site, Al is bonded in a 12-coordinate geometry to two Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.80–2.98 Å. In the fourteenth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and eleven Al atoms. There are a spread of Al–Al bond distances ranging from 2.76–3.09 Å. In the fifteenth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Cr and eleven Al atoms. Both Al–Cr bond lengths are 2.77 Å. There are a spread of Al–Al bond distances ranging from 2.76–3.09 Å. In the sixteenth Al site, Al is bonded in a 12-coordinate geometry to one Cr and ten Al atoms. There are one shorter (2.76 Å) and three longer (2.92 Å) Al–Al bond lengths. In the seventeenth Al site, Al is bonded in a 12-coordinate geometry to one Cr and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.76–3.09 Å. In the eighteenth Al site, Al is bonded in a 11-coordinate geometry to one Cr and ten Al atoms. The Al–Al bond length is 2.83 Å.