DOE OSTI2020
Mg17RhAl11 is gamma-brass-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are eleven inequivalent Mg sites. In the first Mg site, Mg is bonded in a 1-coordinate geometry to five Mg, one Rh, and four Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.01–3.18 Å. The Mg–Rh bond length is 2.81 Å. There are two shorter (2.98 Å) and two longer (3.23 Å) Mg–Al bond lengths. In the second Mg site, Mg is bonded in a 11-coordinate geometry to four Mg, one Rh, and six Al atoms. There are a spread of Mg–Mg bond distances ranging from 2.99–3.21 Å. The Mg–Rh bond length is 3.43 Å. There are a spread of Mg–Al bond distances ranging from 3.10–3.12 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to eight Mg and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.11–3.45 Å. There are a spread of Mg–Al bond distances ranging from 2.89–3.15 Å. In the fourth Mg site, Mg is bonded in a 10-coordinate geometry to five Mg and six Al atoms. There are two shorter (3.02 Å) and one longer (3.16 Å) Mg–Mg bond lengths. There are a spread of Mg–Al bond distances ranging from 3.04–3.17 Å. In the fifth Mg site, Mg is bonded in a 1-coordinate geometry to four Mg, one Rh, and eleven Al atoms. Both Mg–Mg bond lengths are 3.06 Å. The Mg–Rh bond length is 3.03 Å. There are a spread of Mg–Al bond distances ranging from 3.07–3.23 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg, one Rh, and four Al atoms. There are a spread of Mg–Mg bond distances ranging from 2.96–3.19 Å. The Mg–Rh bond length is 3.14 Å. There are a spread of Mg–Al bond distances ranging from 2.91–3.03 Å. In the seventh Mg site, Mg is bonded in a 3-coordinate geometry to six Mg, one Rh, and four Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.12–3.22 Å. The Mg–Rh bond length is 2.88 Å. There are a spread of Mg–Al bond distances ranging from 2.86–3.19 Å. In the eighth 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 3.08–3.17 Å. There are a spread of Mg–Al bond distances ranging from 2.89–3.24 Å. In the ninth Mg site, Mg is bonded in a 1-coordinate geometry to four Mg, one Rh, and five Al atoms. There are one shorter (3.04 Å) and one longer (3.08 Å) Mg–Mg bond lengths. The Mg–Rh bond length is 2.97 Å. There are a spread of Mg–Al bond distances ranging from 2.96–3.11 Å. In the tenth Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. The Mg–Mg bond length is 3.10 Å. There are a spread of Mg–Al bond distances ranging from 2.87–3.19 Å. In the eleventh Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are a spread of Mg–Al bond distances ranging from 2.92–3.15 Å. Rh is bonded in a 12-coordinate geometry to nine Mg and three Al atoms. There are one shorter (2.54 Å) and two longer (2.60 Å) Rh–Al bond lengths. There are six inequivalent Al sites. In the first Al site, Al is bonded in a 1-coordinate geometry to eight Mg, one Rh, and two equivalent Al atoms. Both Al–Al bond lengths are 2.79 Å. In the second Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. There are a spread of Al–Al bond distances ranging from 2.66–2.76 Å. In the third Al site, Al is bonded in a 1-coordinate geometry to eight Mg, one Rh, and one Al atom. The Al–Al bond length is 2.69 Å. In the fourth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. There are one shorter (2.70 Å) and one longer (2.74 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. The Al–Al bond length is 2.75 Å. In the sixth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms.