DOE OSTI2020
Er6Al3Si crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are three inequivalent Er sites. In the first Er site, Er is bonded to five Al atoms to form a mixture of distorted edge and corner-sharing ErAl5 trigonal bipyramids. There are a spread of Er–Al bond distances ranging from 3.11–3.39 Å. In the second Er site, Er is bonded in a 6-coordinate geometry to four Al and two Si atoms. There are a spread of Er–Al bond distances ranging from 2.98–3.30 Å. There are one shorter (2.95 Å) and one longer (3.13 Å) Er–Si bond lengths. In the third Er site, Er is bonded in a 4-coordinate geometry to six Al atoms. There are a spread of Er–Al bond distances ranging from 2.98–3.65 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a 9-coordinate geometry to nine Er atoms. In the second Al site, Al is bonded in a 10-coordinate geometry to nine Er and one Al atom. The Al–Al bond length is 2.74 Å. There are two inequivalent Si sites. In the first Si site, Si is bonded in a body-centered cubic geometry to eight equivalent Er atoms. In the second Si site, Si is bonded in a 8-coordinate geometry to eight equivalent Er atoms.