Materials Data on MgSi2 by Materials Project

Abstract

MgSi2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded in a 1-coordinate geometry to ten Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–3.13 Å. In the second Mg site, Mg is bonded in a 8-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.85–3.03 Å. There are four inequivalent Si sites. In the first Si site, Si is bonded in a 7-coordinate geometry to four Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.36–2.45 Å. In the second Si site, Si is bonded in a 10-coordinate geometry to six Mg and four Si atoms. There are three shorter (2.51 Å) and one longer (2.53 Å) Si–Si bond lengths. In the third Si site, Si is bonded to four equivalent Mg and three Si atoms to form a mixture of distorted edge and corner-sharing SiMg4Si3 pentagonal bipyramids. The Si–Si bond length is 2.40 Å. In the fourth Si site, Si is bonded to four equivalent Mg and four Si atoms to form a mixture of distorted face, edge, and corner-sharing SiMg4Si4 hexagonal bipyramids.