Materials Data on Mg2Si3 by Materials Project

Mg2Si3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 7-coordinate geometry to seven Si+1.33- atoms. There are a spread of Mg–Si bond distances ranging from 2.78–2.88 Å. In the second Mg2+ site, Mg2+ is bonded to six Si+1.33- atoms to form a mixture of distorted edge, face, and corner-sharing MgSi6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 54°. There are a spread of Mg–Si bond distances ranging from 2.79–2.87 Å. In the third Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six Si+1.33- atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.08 Å. In the fourth Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six Si+1.33- atoms. There are a spread of Mg–Si bond distances ranging from 2.74–3.13 Å. In the fifth Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight Si+1.33- atoms. There are a spread of Mg–Si bond distances ranging from 2.82–2.93 Å. In the sixth Mg2+ site, Mg2+ is bonded in a 7-coordinate geometry to seven Si+1.33- atoms. There are a spread of Mg–Si bond distances ranging from 2.79–2.86 Å. In the seventh Mg2+ site, Mg2+ is bonded to six Si+1.33- atoms to form a mixture of distorted edge, face, and corner-sharing MgSi6 octahedra. There are a spread of Mg–Si bond distances ranging from 2.74–3.11 Å. In the eighth Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six Si+1.33- atoms. There are a spread of Mg–Si bond distances ranging from 2.68–3.14 Å. There are twelve inequivalent Si+1.33- sites. In the first Si+1.33- site, Si+1.33- is bonded in a 6-coordinate geometry to three Mg2+ and three Si+1.33- atoms. There are a spread of Si–Si bond distances ranging from 2.41–2.43 Å. In the second Si+1.33- site, Si+1.33- is bonded in a 1-coordinate geometry to three Mg2+ and three Si+1.33- atoms. Both Si–Si bond lengths are 2.42 Å. In the third Si+1.33- site, Si+1.33- is bonded in a 7-coordinate geometry to four Mg2+ and three Si+1.33- atoms. The Si–Si bond length is 2.42 Å. In the fourth Si+1.33- site, Si+1.33- is bonded in a 7-coordinate geometry to four Mg2+ and three Si+1.33- atoms. The Si–Si bond length is 2.43 Å. In the fifth Si+1.33- site, Si+1.33- is bonded in a 8-coordinate geometry to six Mg2+ and two Si+1.33- atoms. There are one shorter (2.44 Å) and one longer (2.45 Å) Si–Si bond lengths. In the sixth Si+1.33- site, Si+1.33- is bonded in a 8-coordinate geometry to six Mg2+ and two Si+1.33- atoms. There are one shorter (2.42 Å) and one longer (2.45 Å) Si–Si bond lengths. In the seventh Si+1.33- site, Si+1.33- is bonded in a 5-coordinate geometry to two Mg2+ and three Si+1.33- atoms. There are two shorter (2.40 Å) and one longer (2.43 Å) Si–Si bond lengths. In the eighth Si+1.33- site, Si+1.33- is bonded in a 7-coordinate geometry to four Mg2+ and three Si+1.33- atoms. There are one shorter (2.44 Å) and one longer (2.45 Å) Si–Si bond lengths. In the ninth Si+1.33- site, Si+1.33- is bonded in a 7-coordinate geometry to four Mg2+ and three Si+1.33- atoms. In the tenth Si+1.33- site, Si+1.33- is bonded in a 7-coordinate geometry to four Mg2+ and three Si+1.33- atoms. In the eleventh Si+1.33- site, Si+1.33- is bonded in a 8-coordinate geometry to six Mg2+ and two Si+1.33- atoms. In the twelfth Si+1.33- site, Si+1.33- is bonded in a 8-coordinate geometry to six Mg2+ and two Si+1.33- atoms.