Materials Data on Mg9Si5 by Materials Project

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 four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–2.86 Å. In the second 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 2.77–2.99 Å. In the third Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–3.14 Å. In the fourth Mg site, Mg is bonded in a distorted tetrahedral geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–2.86 Å. In the fifth Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–3.16 Å. In the sixth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are two shorter (2.74 Å) and one longer (2.97 Å) Mg–Si bond lengths. In the seventh Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.75–3.13 Å. In the eighth Mg site, Mg is bonded in a 1-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.80–3.14 Å. In the ninth 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 2.73–2.93 Å. In the tenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.65–2.84 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.73–3.20 Å. In the twelfth 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 2.75–3.05 Å. In the thirteenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.86–3.03 Å. In the fourteenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.63–2.91 Å. In the fifteenth 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 2.70–3.01 Å. In the sixteenth Mg site, Mg is bonded in a 4-coordinate geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.71–2.93 Å. In the seventeenth 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 2.82–3.06 Å. In the eighteenth 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 2.75–2.99 Å. There are ten inequivalent Si sites. In the first Si site, Si is bonded in a 7-coordinate geometry to six Mg and one Si atom. The Si–Si bond length is 2.44 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 seven Mg and two Si atoms. There are one shorter (2.47 Å) and one longer (2.50 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 9-coordinate geometry to eight Mg and one Si atom. In the fifth Si site, Si is bonded in a 7-coordinate geometry to six Mg and one Si atom. The Si–Si bond length is 2.56 Å. In the sixth Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. In the seventh Si site, Si is bonded in a 10-coordinate geometry to nine Mg and one Si atom. The Si–Si bond length is 2.49 Å. 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 eight Mg atoms. In the tenth Si site, Si is bonded in a 8-coordinate geometry to eight Mg atoms.