Materials Data on Mg2Si by Materials Project

Abstract

Mg2Si crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a distorted trigonal non-coplanar geometry to three Si4- atoms. There are a spread of Mg–Si bond distances ranging from 2.66–2.77 Å. In the second Mg2+ site, Mg2+ is bonded to five Si4- atoms to form distorted MgSi5 trigonal bipyramids that share corners with two equivalent MgSi4 tetrahedra, corners with two equivalent MgSi5 trigonal bipyramids, edges with four equivalent MgSi4 tetrahedra, and edges with three equivalent MgSi5 trigonal bipyramids. There are a spread of Mg–Si bond distances ranging from 2.73–2.94 Å. In the third Mg2+ site, Mg2+ is bonded to four Si4- atoms to form distorted MgSi4 tetrahedra that share corners with two equivalent MgSi4 tetrahedra, corners with two equivalent MgSi5 trigonal bipyramids, an edgeedge with one MgSi4 tetrahedra, and edges with four equivalent MgSi5 trigonal bipyramids. There are a spread of Mg–Si bond distances ranging from 2.80–2.97 Å. In the fourth Mg2+ site, Mg2+ is bonded in a distorted T-shaped geometry to three Si4- atoms. There are a spread of Mg–Si bond distances ranging from 2.67–2.78 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 8-coordinate geometry to seven Mg2+ and one Si4- atom. The Si–Si bond length is 2.43 Å. In the second Si4- site, Si4- is bonded in a 8-coordinate geometry to eight Mg2+ atoms.