Materials Data on Mg16PaAl12 by Materials Project
Mg16PaAl12 is gamma-brass-derived structured and 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 10-coordinate geometry to three equivalent Mg, one Pa, and twelve Al atoms. All Mg–Mg bond lengths are 3.18 Å. The Mg–Pa bond length is 3.29 Å. There are a spread of Mg–Al bond distances ranging from 3.16–3.24 Å. In the second Mg site, Mg is bonded in a 3-coordinate geometry to one Pa and five Al atoms. The Mg–Pa bond length is 3.61 Å. There are a spread of Mg–Al bond distances ranging from 2.85–3.23 Å. In the third Mg site, Mg is bonded in a 11-coordinate geometry to one Mg and six Al atoms. There are a spread of Mg–Al bond distances ranging from 3.05–3.13 Å. In the fourth Mg site, Mg is bonded in a 6-coordinate geometry to one Pa and five Al atoms. The Mg–Pa bond length is 3.14 Å. There are a spread of Mg–Al bond distances ranging from 2.81–3.11 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to four Al atoms. There are a spread of Mg–Al bond distances ranging from 2.97–3.20 Å. Pa is bonded in a 3-coordinate geometry to seven Mg and nine Al atoms. There are three shorter (3.19 Å) and six longer (3.20 Å) Pa–Al bond lengths. There are three inequivalent Al sites. In the first Al site, Al is bonded in a 12-coordinate geometry to six Mg, one Pa, and three Al atoms. There are one shorter (2.66 Å) and two longer (2.75 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 2.76 Å. In the third Al site, Al is bonded in a distorted q6 geometry to seven Mg, one Pa, and three Al atoms. There are one shorter (2.72 Å) and one longer (2.77 Å) Al–Al bond lengths.