Materials Data on Mg2Si by Materials Project

Abstract

Mg2Si crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a hexagonal planar geometry to six Si4- atoms. There are four shorter (2.95 Å) and two longer (2.96 Å) Mg–Si bond lengths. In the second Mg2+ site, Mg2+ is bonded to five Si4- atoms to form a mixture of distorted corner, edge, and face-sharing MgSi5 trigonal bipyramids. There are a spread of Mg–Si bond distances ranging from 2.89–3.04 Å. In the third Mg2+ site, Mg2+ is bonded in a square co-planar geometry to four Si4- atoms. There are a spread of Mg–Si bond distances ranging from 2.95–3.07 Å. There are three inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 11-coordinate geometry to eleven Mg2+ atoms. In the second Si4- site, Si4- is bonded in a distorted q6 geometry to ten Mg2+ atoms. In the third Si4- site, Si4- is bonded in a distorted body-centered cubic geometry to eight Mg2+ atoms.