DOI: 10.17188/1680878
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 10-coordinate geometry to ten Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.00 Å. In the second Mg site, Mg is bonded in a distorted rectangular see-saw-like geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.69–2.90 Å. In the third Mg site, Mg is bonded to seven Si atoms to form distorted MgSi7 square pyramids that share edges with two equivalent SiMg2Si5 pentagonal bipyramids and faces with two equivalent MgSi7 square pyramids. There are a spread of Mg–Si bond distances ranging from 2.75–3.23 Å. In the fourth 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 2.82–3.08 Å. In the fifth Mg site, Mg is bonded in a 10-coordinate geometry to ten Si atoms. There are a spread of Mg–Si bond distances ranging from 2.88–3.04 Å. In the sixth Mg site, Mg is bonded in a 9-coordinate geometry to nine Si atoms. There are a spread of Mg–Si bond distances ranging from 2.65–2.99 Å. In the seventh Mg site, Mg is bonded in a 6-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.81–3.17 Å. In the eighth 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 2.86–2.99 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 2.47–2.54 Å. In the second 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 2.40–2.45 Å. In the third Si site, Si is bonded in a 6-coordinate geometry to two Mg and four Si atoms. There are one shorter (2.45 Å) and one longer (2.73 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 2-coordinate geometry to two Mg and five Si atoms. There are one shorter (2.68 Å) and one longer (2.72 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.40 Å) and one longer (2.41 Å) Si–Si bond lengths. In the sixth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. The Si–Si bond length is 2.44 Å. In the seventh Si site, Si is bonded to two equivalent Mg and five Si atoms to form distorted SiMg2Si5 pentagonal bipyramids that share edges with two equivalent MgSi7 square pyramids and faces with two equivalent SiMg2Si5 pentagonal bipyramids. There are a spread of Si–Si bond distances ranging from 2.53–2.70 Å. In the eighth Si site, Si is bonded in a 9-coordinate geometry to five Mg and four Si atoms. There are a spread of Si–Si bond distances ranging from 2.47–2.51 Å. In the ninth Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.49–2.55 Å. In the tenth Si site, Si is bonded in a 1-coordinate geometry to two Mg and five Si atoms. There are one shorter (2.62 Å) and one longer (2.73 Å) Si–Si bond lengths. In the eleventh Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. The Si–Si bond length is 2.61 Å. In the twelfth Si site, Si is bonded in a 9-coordinate geometry to five 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 10-coordinate geometry to six Mg and four Si atoms.