Materials Data on MgSi by Materials Project

Abstract

MgSi crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are six inequivalent Mg sites. In the first Mg site, Mg is bonded in a 6-coordinate geometry to two equivalent Mg and six Si atoms. Both Mg–Mg bond lengths are 3.32 Å. There are a spread of Mg–Si bond distances ranging from 2.83–3.01 Å. In the second Mg site, Mg is bonded in a 7-coordinate geometry to seven Si atoms. There are a spread of Mg–Si bond distances ranging from 2.83–3.00 Å. In the third Mg site, Mg is bonded in a 6-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–3.13 Å. In the fourth Mg site, Mg is bonded in a 12-coordinate geometry to four Mg and eight Si atoms. Both Mg–Mg bond lengths are 3.26 Å. There are a spread of Mg–Si bond distances ranging from 2.87–3.23 Å. In the fifth Mg site, Mg is bonded to four Si atoms to form distorted MgSi4 tetrahedra that share corners with two equivalent MgSi4 tetrahedra and edges with two equivalent MgMg2Si4 tetrahedra. There are a spread of Mg–Si bond distances ranging from 2.66–2.78 Å. In the sixth Mg site, Mg is bonded to two equivalent Mg and four Si atoms to form edge-sharing MgMg2Si4 tetrahedra. There are a spread of Mg–Si bond distances ranging from 2.62–2.71 Å. There are six inequivalent Si sites. In the first Si site, Si is bonded in a 1-coordinate geometry to six Mg and two equivalent Si atoms. Both Si–Si bond lengths are 2.40 Å. In the second Si site, Si is bonded in a 1-coordinate geometry to five Mg and three Si atoms. There are one shorter (2.50 Å) and two longer (2.52 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Si–Si bond length is 2.34 Å. In the fourth Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the fifth Si site, Si is bonded in a 8-coordinate geometry to five Mg and three Si atoms. The Si–Si bond length is 2.57 Å. In the sixth Si site, Si is bonded in a 7-coordinate geometry to three Mg and four Si atoms.