DOI: 10.17188/1742268
title: Materials Data on Mg4Si7 by Materials Project

description: Mg4Si7 is Magnesium tetraboride-like structured and 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 9-coordinate geometry to one Mg and thirteen Si atoms. The Mg–Mg bond length is 3.19 Å. There are a spread of Mg–Si bond distances ranging from 2.87–3.18 Å. In the second Mg site, Mg is bonded in a distorted rectangular see-saw-like geometry to two equivalent Mg and four Si atoms. There are one shorter (3.06 Å) and one longer (3.31 Å) Mg–Mg bond lengths. There are a spread of Mg–Si bond distances ranging from 2.68–2.87 Å. In the third Mg site, Mg is bonded in a 6-coordinate geometry to one Mg and six Si atoms. The Mg–Mg bond length is 3.24 Å. There are a spread of Mg–Si bond distances ranging from 2.78–3.11 Å. In the fourth Mg site, Mg is bonded in a 6-coordinate geometry to two equivalent Mg and six Si atoms. There are one shorter (3.21 Å) and one longer (3.41 Å) Mg–Mg bond lengths. There are a spread of Mg–Si bond distances ranging from 2.79–3.08 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to three Mg and nine Si atoms. There are a spread of Mg–Si bond distances ranging from 2.81–3.16 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 2.57–3.01 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 2.80–3.12 Å. In the eighth Mg site, Mg is bonded in a 2-coordinate geometry to three Mg and eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–3.14 Å. There are fourteen inequivalent Si sites. In the first Si site, Si is bonded in a 7-coordinate geometry to four Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.40–2.52 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 2.40–2.52 Å. In the third Si site, Si is bonded in a 6-coordinate geometry to two Mg and four Si atoms. The Si–Si bond length is 2.52 Å. In the fourth Si site, Si is bonded to three Mg and four Si atoms to form distorted edge-sharing SiMg3Si4 hexagonal pyramids. There are one shorter (2.38 Å) and one longer (2.47 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. There are one shorter (2.42 Å) and one longer (2.44 Å) Si–Si bond lengths. 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 2.45 Å. In the seventh Si site, Si is bonded in a 6-coordinate geometry to three Mg and three Si atoms. The Si–Si bond length is 2.30 Å. In the eighth 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 2.43–2.51 Å. In the ninth Si site, Si is bonded in a 1-coordinate geometry to six Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.46–2.49 Å. In the tenth Si site, Si is bonded in a 6-coordinate geometry to two Mg and four Si atoms. There are one shorter (2.43 Å) and one longer (2.49 Å) Si–Si bond lengths. In the eleventh Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. The Si–Si bond length is 2.41 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 6-coordinate geometry to two equivalent Mg and four Si atoms.