Materials Data on Mg9Si5 by Materials Project

Abstract

Mg9Si5 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eighteen inequivalent Mg sites. In the first Mg site, Mg is bonded in a 4-coordinate geometry to two equivalent Mg and five Si atoms. There are one shorter (2.93 Å) and one longer (3.04 Å) Mg–Mg bond lengths. There are a spread of Mg–Si bond distances ranging from 2.65–3.09 Å. In the second Mg site, Mg is bonded in a 4-coordinate geometry to two Mg and four Si atoms. There are one shorter (3.08 Å) and one longer (3.25 Å) Mg–Mg bond lengths. There are a spread of Mg–Si bond distances ranging from 2.75–2.91 Å. In the third Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Si atoms. There are a spread of Mg–Mg bond distances ranging from 2.99–3.17 Å. There are a spread of Mg–Si bond distances ranging from 2.86–3.10 Å. In the fourth Mg site, Mg is bonded in a 3-coordinate geometry to one Mg and four Si atoms. The Mg–Mg bond length is 3.03 Å. There are a spread of Mg–Si bond distances ranging from 2.83–3.17 Å. In the fifth 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 2.88–2.99 Å. In the sixth Mg site, Mg is bonded in a 4-coordinate geometry to one Mg and four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.76–2.94 Å. In the seventh Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Mg and four Si atoms. There are one shorter (3.09 Å) and one longer (3.25 Å) Mg–Mg bond lengths. There are a spread of Mg–Si bond distances ranging from 2.81–3.06 Å. In the eighth Mg site, Mg is bonded to four Si atoms to form distorted MgSi4 trigonal pyramids that share a cornercorner with one MgMgSi4 tetrahedra and corners with two equivalent MgSi4 trigonal pyramids. There are a spread of Mg–Si bond distances ranging from 2.73–3.00 Å. In the ninth Mg site, Mg is bonded in a 4-coordinate geometry to one Mg and four Si atoms. The Mg–Mg bond length is 3.13 Å. There are a spread of Mg–Si bond distances ranging from 2.71–2.86 Å. In the tenth Mg site, Mg is bonded in a distorted T-shaped geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.80–2.92 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.85–2.98 Å. In the twelfth Mg site, Mg is bonded in a 2-coordinate geometry to three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.68–2.99 Å. In the thirteenth Mg site, Mg is bonded to one Mg and four Si atoms to form distorted MgMgSi4 tetrahedra that share corners with two equivalent MgMgSi4 tetrahedra and a cornercorner with one MgSi4 trigonal pyramid. The Mg–Mg bond length is 2.92 Å. There are one shorter (2.78 Å) and three longer (2.82 Å) Mg–Si bond lengths. In the fourteenth 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 2.82–3.13 Å. In the fifteenth Mg site, Mg is bonded in a 4-coordinate geometry to one Mg and four Si atoms. The Mg–Mg bond length is 2.96 Å. There are a spread of Mg–Si bond distances ranging from 2.69–3.04 Å. In the sixteenth Mg site, Mg is bonded in a 5-coordinate geometry to five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–3.03 Å. In the seventeenth Mg site, Mg is bonded in a 4-coordinate geometry to seven Mg and four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.88–3.07 Å. In the eighteenth Mg site, Mg is bonded in a 3-coordinate geometry to one Mg and five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.69–3.18 Å. There are ten inequivalent Si sites. In the first Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. The Si–Si bond length is 2.51 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the third Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Si–Si bond length is 2.52 Å. In the fourth Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. The Si–Si bond length is 2.56 Å. In the fifth Si site, Si is bonded in a 5-coordinate geometry to five Mg atoms. In the sixth Si site, Si is bonded in a 8-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.62 Å) and one longer (2.83 Å) Si–Si bond lengths. In the seventh Si site, Si is bonded in a 9-coordinate geometry to nine Mg atoms. In the eighth Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. In the ninth Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the tenth Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom.