DOE OSTI2020
Mg4Si3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Mg sites. In the first 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 2.76–2.99 Å. In the second 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 2.78–2.84 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to six Mg and five Si atoms. There are a spread of Mg–Mg bond distances ranging from 2.95–3.20 Å. There are a spread of Mg–Si bond distances ranging from 2.82–3.04 Å. In the fourth Mg site, Mg is bonded in a 3-coordinate geometry to three Si atoms. There are two shorter (2.89 Å) and one longer (3.02 Å) Mg–Si bond lengths. In the fifth Mg site, Mg is bonded in a 2-coordinate geometry to one Mg and four Si atoms. The Mg–Mg bond length is 3.17 Å. There are a spread of Mg–Si bond distances ranging from 2.85–3.01 Å. In the sixth Mg site, Mg is bonded in a 2-coordinate geometry to one Mg and six Si atoms. The Mg–Mg bond length is 3.00 Å. There are a spread of Mg–Si bond distances ranging from 2.73–3.18 Å. In the seventh 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 2.76–3.01 Å. In the eighth 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 2.86–3.16 Å. In the ninth Mg site, Mg is bonded in a 5-coordinate geometry to one Mg and five Si atoms. The Mg–Mg bond length is 3.05 Å. There are a spread of Mg–Si bond distances ranging from 2.72–2.94 Å. In the tenth Mg site, Mg is bonded in a 5-coordinate geometry to one Mg and five Si atoms. The Mg–Mg bond length is 3.00 Å. There are a spread of Mg–Si bond distances ranging from 2.83–3.00 Å. In the eleventh Mg site, Mg is bonded in a 3-coordinate geometry to one Mg and three Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–2.84 Å. In the twelfth Mg site, Mg is bonded in a 4-coordinate geometry to one Mg and five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.74–3.20 Å. In the thirteenth Mg site, Mg is bonded in a 11-coordinate geometry to six Mg and five Si atoms. The Mg–Mg bond length is 3.18 Å. There are a spread of Mg–Si bond distances ranging from 2.78–3.25 Å. In the fourteenth Mg site, Mg is bonded in a 2-coordinate geometry to two Mg and five Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.11 Å. In the fifteenth 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 2.72–3.11 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 2.84–3.08 Å. There are twelve inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.46–2.69 Å. In the second Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.48 Å) and one longer (2.69 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 8-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.37 Å) and one longer (2.50 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 8-coordinate geometry to five Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.47–2.80 Å. In the fifth Si site, Si is bonded in a 7-coordinate geometry to six Mg and two Si atoms. There are one shorter (2.49 Å) and one longer (2.58 Å) Si–Si bond lengths. In the sixth Si site, Si is bonded in a 11-coordinate geometry to six Mg and two Si atoms. In the seventh Si site, Si is bonded in a 8-coordinate geometry to seven Mg and one Si atom. The Si–Si bond length is 2.42 Å. In the eighth Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. The Si–Si bond length is 2.54 Å. In the ninth Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. In the tenth Si site, Si is bonded in a 10-coordinate geometry to eight Mg and two Si atoms. In the eleventh Si site, Si is bonded in a 8-coordinate geometry to five Mg and three Si atoms. In the twelfth Si site, Si is bonded in a 7-coordinate geometry to five Mg and two Si atoms.