Materials Data on Mg16UAl12 by Materials Project
Mg16UAl12 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are five inequivalent Mg sites. In the first Mg site, Mg is bonded in a 3-coordinate geometry to two equivalent Mg and five Al atoms. Both Mg–Mg bond lengths are 3.31 Å. There are a spread of Mg–Al bond distances ranging from 2.85–3.22 Å. In the second Mg site, Mg is bonded in a 1-coordinate geometry to seven Mg, one U, and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.13–3.39 Å. The Mg–U bond length is 3.13 Å. There are a spread of Mg–Al bond distances ranging from 2.82–3.10 Å. In the third Mg site, Mg is bonded in a 9-coordinate geometry to three equivalent Mg, one U, and twelve Al atoms. All Mg–Mg bond lengths are 3.16 Å. The Mg–U bond length is 3.29 Å. There are a spread of Mg–Al bond distances ranging from 3.17–3.23 Å. In the fourth Mg site, Mg is bonded in a 10-coordinate geometry to two Mg and six Al atoms. There are a spread of Mg–Al bond distances ranging from 3.06–3.12 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to two equivalent Mg and four Al atoms. There are a spread of Mg–Al bond distances ranging from 2.96–3.20 Å. U is bonded in a 12-coordinate geometry to four Mg and nine Al atoms. All U–Al bond lengths are 3.18 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 10-coordinate geometry to six Mg, one U, and three Al atoms. There are one shorter (2.66 Å) and two longer (2.74 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. Both Al–Al bond lengths are 2.77 Å. In the third Al site, Al is bonded in a distorted q6 geometry to seven Mg, one U, and three Al atoms. There are one shorter (2.71 Å) and one longer (2.75 Å) Al–Al bond lengths.