Materials Data on Mg4Si7 by Materials Project

Abstract

Mg4Si7 crystallizes in the monoclinic Pm 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 eleven Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.20 Å. In the second Mg site, Mg is bonded in a square co-planar geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–2.85 Å. In the third Mg site, Mg is bonded to seven Si atoms to form distorted face-sharing MgSi7 square pyramids. There are a spread of Mg–Si bond distances ranging from 2.75–3.17 Å. In the fourth Mg site, Mg is bonded in a 6-coordinate geometry to two equivalent Mg and eight Si atoms. Both Mg–Mg bond lengths are 3.28 Å. There are a spread of Mg–Si bond distances ranging from 2.84–3.21 Å. In the fifth Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Mg and eleven Si atoms. There are a spread of Mg–Si bond distances ranging from 2.85–3.21 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to eleven Si atoms. There are a spread of Mg–Si bond distances ranging from 2.64–3.13 Å. In the seventh 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 2.79–2.99 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 2.82–2.95 Å. There are fourteen inequivalent Si sites. In the first Si site, Si is bonded in a 10-coordinate geometry to five Mg and five Si atoms. There are a spread of Si–Si bond distances ranging from 2.48–2.82 Å. In the second Si site, Si is bonded in a 10-coordinate geometry to four Mg and six Si atoms. There are a spread of Si–Si bond distances ranging from 2.40–2.93 Å. In the third Si site, Si is bonded in a 1-coordinate geometry to three Mg and four Si atoms. In the fourth Si site, Si is bonded in a 8-coordinate geometry to three Mg and five Si atoms. There are two shorter (2.48 Å) and one longer (2.81 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 (2.38 Å) and one longer (2.42 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 2.46 Å. In the seventh Si site, Si is bonded in a 9-coordinate geometry to four Mg and five Si atoms. There are one shorter (2.47 Å) and two longer (2.75 Å) Si–Si bond lengths. In the eighth Si site, Si is bonded in a 9-coordinate geometry to five Mg and four Si atoms. There are two shorter (2.43 Å) and one longer (2.67 Å) Si–Si bond lengths. In the ninth Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. All Si–Si bond lengths are 2.52 Å. In the tenth Si site, Si is bonded in a 2-coordinate geometry to two Mg and six Si atoms. Both Si–Si bond lengths are 2.61 Å. 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 2.53 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 10-coordinate geometry to six Mg and four Si atoms. In the fourteenth Si site, Si is bonded in a 8-coordinate geometry to four Mg and four Si atoms.