DOE OSTI2020
Mg6CeFe crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 11-coordinate geometry to eight Mg, two equivalent Ce, and one Fe atom. There are a spread of Mg–Mg bond distances ranging from 2.86–3.40 Å. There are one shorter (3.40 Å) and one longer (3.43 Å) Mg–Ce bond lengths. The Mg–Fe bond length is 3.09 Å. In the second Mg site, Mg is bonded in a 10-coordinate geometry to six Mg, two equivalent Ce, and two equivalent Fe atoms. There are a spread of Mg–Mg bond distances ranging from 2.80–3.19 Å. Both Mg–Ce bond lengths are 3.20 Å. Both Mg–Fe bond lengths are 3.04 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to eight Mg and two equivalent Fe atoms. Both Mg–Mg bond lengths are 2.94 Å. Both Mg–Fe bond lengths are 3.02 Å. In the fourth Mg site, Mg is bonded in a 10-coordinate geometry to eight Mg and two equivalent Ce atoms. Both Mg–Ce bond lengths are 3.20 Å. Ce is bonded in a 12-coordinate geometry to ten Mg and two equivalent Fe atoms. Both Ce–Fe bond lengths are 2.89 Å. Fe is bonded in a 10-coordinate geometry to eight Mg and two equivalent Ce atoms.