Materials Data on Mg7Si4 by Materials Project

Abstract

Mg7Si4 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are fourteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to two equivalent Mg and four Si atoms. Both Mg–Mg bond lengths are 3.11 Å. There are a spread of Mg–Si bond distances ranging from 2.70–2.98 Å. In the second Mg site, Mg is bonded in a 10-coordinate geometry to nine Mg and one Si atom. There are a spread of Mg–Mg bond distances ranging from 3.04–3.33 Å. The Mg–Si bond length is 3.17 Å. In the third Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Mg and three Si atoms. There are two shorter (2.78 Å) and one longer (2.92 Å) Mg–Si bond lengths. In the fourth Mg site, Mg is bonded in a 3-coordinate geometry to two equivalent Mg and three Si atoms. There are two shorter (2.87 Å) and one longer (3.08 Å) Mg–Si bond lengths. In the fifth Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Mg and five Si atoms. There are one shorter (3.00 Å) and one longer (3.01 Å) Mg–Mg bond lengths. There are a spread of Mg–Si bond distances ranging from 2.85–2.93 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.88–3.18 Å. In the seventh Mg site, Mg is bonded in a 4-coordinate geometry to two equivalent Mg and four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.99–3.03 Å. In the eighth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Mg and two equivalent Si atoms. Both Mg–Si bond lengths are 2.85 Å. In the ninth Mg site, Mg is bonded in a distorted bent 120 degrees geometry to two Si atoms. There are one shorter (2.90 Å) and one longer (2.94 Å) Mg–Si bond lengths. In the tenth Mg site, Mg is bonded in a 1-coordinate geometry to eight Mg and two Si atoms. There are a spread of Mg–Mg bond distances ranging from 2.96–3.17 Å. There are one shorter (2.93 Å) and one longer (3.14 Å) Mg–Si bond lengths. In the eleventh Mg site, Mg is bonded in a 4-coordinate geometry to two equivalent Mg and four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.95–3.10 Å. In the twelfth Mg site, Mg is bonded in a 3-coordinate geometry to two equivalent Mg and three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–2.78 Å. In the thirteenth Mg site, Mg is bonded in a distorted single-bond geometry to one Mg and three Si atoms. There are one shorter (2.69 Å) and two longer (3.12 Å) Mg–Si bond lengths. In the fourteenth Mg site, Mg is bonded in a distorted single-bond geometry to one Si atom. The Mg–Si bond length is 2.84 Å. There are eight inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to five Mg and three Si atoms. There are one shorter (2.45 Å) and two longer (2.47 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 8-coordinate geometry to six Mg and two equivalent Si atoms. Both Si–Si bond lengths are 2.39 Å. In the third Si site, Si is bonded in a 7-coordinate geometry to four Mg and three Si atoms. There are two shorter (2.43 Å) and one longer (2.44 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. There are two shorter (2.50 Å) and one longer (2.52 Å) Si–Si bond lengths. In the fifth Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. In the sixth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two equivalent Si atoms. In the seventh Si site, Si is bonded in a 7-coordinate geometry to four Mg and three Si atoms. In the eighth Si site, Si is bonded in a 8-coordinate geometry to five Mg and three Si atoms.