Materials Data on Mg9Si5 by Materials Project

Abstract

Mg9Si5 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to four Si atoms to form a mixture of distorted edge and corner-sharing MgSi4 tetrahedra. There are a spread of Mg–Si bond distances ranging from 2.67–2.79 Å. In the second Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are one shorter (2.87 Å) and four longer (2.91 Å) Mg–Si bond lengths. There are three inequivalent Si sites. In the first Si site, Si is bonded in a 7-coordinate geometry to six Mg and one Si atom. The Si–Si bond length is 2.51 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to nine Mg atoms. In the third Si site, Si is bonded in a 9-coordinate geometry to nine Mg atoms.