Materials Data on UAl4 by Materials Project
UAl4 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. U is bonded in a 9-coordinate geometry to thirteen Al atoms. There are a spread of U–Al bond distances ranging from 3.01–3.13 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 3-coordinate geometry to three equivalent U and ten Al atoms. There are a spread of Al–Al bond distances ranging from 2.86–3.07 Å. In the second Al site, Al is bonded in a 10-coordinate geometry to three equivalent U and seven Al atoms. There are a spread of Al–Al bond distances ranging from 2.61–2.77 Å. In the third Al site, Al is bonded to four equivalent U and eight Al atoms to form a mixture of distorted face, edge, and corner-sharing AlU4Al8 cuboctahedra. Both Al–Al bond lengths are 3.12 Å.