Materials Data on Mg6Si5 by Materials Project

Abstract

Mg6Si5 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a distorted T-shaped geometry to three Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.85–3.18 Å. In the second Mg2+ site, Mg2+ is bonded in a 5-coordinate geometry to five Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.79–3.07 Å. In the third Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.66–2.97 Å. In the fourth Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.77–3.18 Å. In the fifth Mg2+ site, Mg2+ is bonded to five Si+2.40- atoms to form distorted MgSi5 trigonal bipyramids that share corners with two equivalent MgSi5 trigonal bipyramids, corners with two equivalent MgSi4 trigonal pyramids, and an edgeedge with one MgSi4 trigonal pyramid. There are a spread of Mg–Si bond distances ranging from 2.77–3.06 Å. In the sixth Mg2+ site, Mg2+ is bonded in a 5-coordinate geometry to five Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.72–3.14 Å. In the seventh Mg2+ site, Mg2+ is bonded in a 6-coordinate geometry to six Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.73–3.07 Å. In the eighth Mg2+ site, Mg2+ is bonded in a distorted rectangular see-saw-like geometry to four Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.71–3.09 Å. In the ninth Mg2+ site, Mg2+ is bonded in a 5-coordinate geometry to five Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.82–3.07 Å. In the tenth Mg2+ site, Mg2+ is bonded in a 3-coordinate geometry to three Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.72–2.93 Å. In the eleventh Mg2+ site, Mg2+ is bonded in a 4-coordinate geometry to four Si+2.40- atoms. There are a spread of Mg–Si bond distances ranging from 2.83–2.98 Å. In the twelfth Mg2+ site, Mg2+ is bonded to four Si+2.40- atoms to form a mixture of distorted corner and edge-sharing MgSi4 trigonal pyramids. There are a spread of Mg–Si bond distances ranging from 2.80–2.89 Å. There are ten inequivalent Si+2.40- sites. In the first Si+2.40- site, Si+2.40- is bonded in a 7-coordinate geometry to six Mg2+ and two Si+2.40- atoms. There are one shorter (2.38 Å) and one longer (2.45 Å) Si–Si bond lengths. In the second Si+2.40- site, Si+2.40- is bonded in a 9-coordinate geometry to six Mg2+ and three Si+2.40- atoms. There are one shorter (2.43 Å) and one longer (2.47 Å) Si–Si bond lengths. In the third Si+2.40- site, Si+2.40- is bonded in a 8-coordinate geometry to six Mg2+ and two Si+2.40- atoms. There are one shorter (2.36 Å) and one longer (2.53 Å) Si–Si bond lengths. In the fourth Si+2.40- site, Si+2.40- is bonded in a 7-coordinate geometry to five Mg2+ and two Si+2.40- atoms. Both Si–Si bond lengths are 2.40 Å. In the fifth Si+2.40- site, Si+2.40- is bonded in a 8-coordinate geometry to five Mg2+ and three Si+2.40- atoms. There are one shorter (2.43 Å) and one longer (2.49 Å) Si–Si bond lengths. In the sixth Si+2.40- site, Si+2.40- is bonded in a 8-coordinate geometry to five Mg2+ and three Si+2.40- atoms. The Si–Si bond length is 2.37 Å. In the seventh Si+2.40- site, Si+2.40- is bonded in a 7-coordinate geometry to four Mg2+ and three Si+2.40- atoms. The Si–Si bond length is 2.44 Å. In the eighth Si+2.40- site, Si+2.40- is bonded in a 8-coordinate geometry to six Mg2+ and two Si+2.40- atoms. In the ninth Si+2.40- site, Si+2.40- is bonded in a 8-coordinate geometry to six Mg2+ and two Si+2.40- atoms. In the tenth Si+2.40- site, Si+2.40- is bonded in a 9-coordinate geometry to seven Mg2+ and two Si+2.40- atoms.