DOI: 10.17188/1748338
title: Materials Data on Mg4Si7 by Materials Project

description: Mg4Si7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to one Mg and eleven Si atoms. The Mg–Mg bond length is 3.33 Å. There are a spread of Mg–Si bond distances ranging from 2.80–3.21 Å. In the second Mg site, Mg is bonded in a rectangular see-saw-like geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.69–2.74 Å. In the third Mg site, Mg is bonded in a 4-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.69–3.06 Å. In the fourth Mg site, Mg is bonded in a 5-coordinate geometry to two equivalent Mg and seven Si atoms. There are one shorter (3.35 Å) and one longer (3.41 Å) Mg–Mg bond lengths. There are a spread of Mg–Si bond distances ranging from 2.79–3.22 Å. In the fifth Mg site, Mg is bonded in a 4-coordinate geometry to three Mg and eleven Si atoms. There are a spread of Mg–Si bond distances ranging from 2.88–3.26 Å. In the sixth 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 2.65–3.04 Å. In the seventh 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 2.82–3.02 Å. In the eighth Mg site, Mg is bonded in a 6-coordinate geometry to nine Si atoms. There are a spread of Mg–Si bond distances ranging from 2.85–3.19 Å. There are fourteen inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to four Mg and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.42–2.52 Å. In the second Si site, Si is bonded in a 7-coordinate geometry to three Mg and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.40–2.51 Å. In the third Si site, Si is bonded in a 2-coordinate geometry to three Mg and three Si atoms. The Si–Si bond length is 2.37 Å. In the fourth Si site, Si is bonded to four Si atoms to form distorted edge-sharing SiSi4 tetrahedra. There are one shorter (2.34 Å) and one longer (2.35 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. Both Si–Si bond lengths are 2.38 Å. In the sixth Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. The Si–Si bond length is 2.41 Å. In the seventh Si site, Si is bonded in a 5-coordinate geometry to two Mg and three Si atoms. There are one shorter (2.36 Å) and one longer (2.41 Å) Si–Si bond lengths. In the eighth Si site, Si is bonded in a 10-coordinate geometry to six Mg and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.43–2.51 Å. In the ninth Si site, Si is bonded in a 10-coordinate geometry to seven Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.48–2.55 Å. In the tenth Si site, Si is bonded to three Mg and three Si atoms to form distorted SiMg3Si3 octahedra that share corners with two equivalent SiMg3Si3 octahedra and an edgeedge with one SiSi4 tetrahedra. The corner-sharing octahedral tilt angles are 87°. In the eleventh Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms. The Si–Si bond length is 2.39 Å. In the twelfth Si site, Si is bonded in a 10-coordinate geometry to six Mg and four Si atoms. In the thirteenth Si site, Si is bonded in a 9-coordinate geometry to five Mg and four Si atoms. In the fourteenth Si site, Si is bonded in a 2-coordinate geometry to four Mg and two Si atoms.