DOE OSTI2020
Mg16ScAl12 is gamma-brass-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are ten inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.09–3.20 Å. There are a spread of Mg–Al bond distances ranging from 2.90–3.16 Å. In the second Mg site, Mg is bonded in a 10-coordinate geometry to three Mg, one Sc, and six Al atoms. There are two shorter (3.05 Å) and one longer (3.16 Å) Mg–Mg bond lengths. The Mg–Sc bond length is 3.06 Å. There are a spread of Mg–Al bond distances ranging from 3.07–3.14 Å. In the third Mg site, Mg is bonded in a 11-coordinate geometry to four Mg, one Sc, and six Al atoms. There are two shorter (3.03 Å) and one longer (3.17 Å) Mg–Mg bond lengths. The Mg–Sc bond length is 3.53 Å. There are a spread of Mg–Al bond distances ranging from 3.07–3.13 Å. In the fourth Mg site, Mg is bonded in a 1-coordinate geometry to four Mg and twelve Al atoms. Both Mg–Mg bond lengths are 3.11 Å. There are a spread of Mg–Al bond distances ranging from 3.15–3.26 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to six Mg, one Sc, and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.06–3.16 Å. The Mg–Sc bond length is 3.14 Å. There are a spread of Mg–Al bond distances ranging from 2.92–3.22 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to six Mg, one Sc, and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.12–3.17 Å. The Mg–Sc bond length is 3.20 Å. There are a spread of Mg–Al bond distances ranging from 2.90–3.19 Å. In the seventh Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are two shorter (3.15 Å) and one longer (3.21 Å) Mg–Mg bond lengths. There are a spread of Mg–Al bond distances ranging from 2.90–3.16 Å. In the eighth Mg site, Mg is bonded in a 10-coordinate geometry to four Mg and six Al atoms. There are one shorter (3.04 Å) and one longer (3.06 Å) Mg–Mg bond lengths. There are a spread of Mg–Al bond distances ranging from 3.05–3.15 Å. In the ninth Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. The Mg–Mg bond length is 3.12 Å. There are a spread of Mg–Al bond distances ranging from 2.90–3.22 Å. In the tenth Mg site, Mg is bonded in a 12-coordinate geometry to six Mg, one Sc, and five Al atoms. The Mg–Sc bond length is 3.20 Å. There are a spread of Mg–Al bond distances ranging from 2.89–3.18 Å. Sc is bonded in a 12-coordinate geometry to eight Mg and five Al atoms. There are a spread of Sc–Al bond distances ranging from 2.91–3.06 Å. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 11-coordinate geometry to seven Mg, one Sc, and three Al atoms. There are one shorter (2.70 Å) and two longer (2.77 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 2.80 Å. In the third Al site, Al is bonded in a 11-coordinate geometry to seven Mg, one Sc, and three Al atoms. There are a spread of Al–Al bond distances ranging from 2.69–2.78 Å. In the fourth Al site, Al is bonded in a 11-coordinate geometry to seven Mg, one Sc, and three Al atoms. There are one shorter (2.72 Å) and one longer (2.76 Å) Al–Al bond lengths. In the fifth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. There are one shorter (2.68 Å) and one longer (2.77 Å) Al–Al bond lengths. In the sixth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. The Al–Al bond length is 2.74 Å. In the seventh Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms.