Materials Data on Mg4AlSi6 by Materials Project
Mg4AlSi6 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded in a 9-coordinate geometry to two Mg, one Al, and eight Si atoms. There are one shorter (2.95 Å) and one longer (3.19 Å) Mg–Mg bond lengths. The Mg–Al bond length is 2.99 Å. There are a spread of Mg–Si bond distances ranging from 2.95–3.04 Å. In the second Mg site, Mg is bonded in a 8-coordinate geometry to one Mg, one Al, and seven Si atoms. The Mg–Al bond length is 2.74 Å. There are a spread of Mg–Si bond distances ranging from 2.77–3.04 Å. Al is bonded in a 8-coordinate geometry to four Mg and four equivalent Si atoms. All Al–Si bond lengths are 2.62 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to six Mg, two equivalent Al, and one Si atom. The Si–Si bond length is 2.40 Å. In the second Si site, Si is bonded in a 8-coordinate geometry to five Mg and three equivalent Si atoms. There are two shorter (2.45 Å) and one longer (2.50 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 8-coordinate geometry to four Mg and four Si atoms.