DOI: 10.17188/1730586
title: Materials Data on Mg5Si6 by Materials Project

description: Mg5Si6 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are ten inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted rectangular see-saw-like geometry to four Si atoms. There are a spread of Mg–Si bond distances ranging from 2.70–2.85 Å. In the second Mg site, Mg is bonded in a distorted T-shaped geometry to three Si atoms. There are two shorter (2.71 Å) and one longer (2.82 Å) Mg–Si bond lengths. In the third 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 2.74–3.16 Å. In the fourth Mg site, Mg is bonded in a 8-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–3.11 Å. In the fifth Mg site, Mg is bonded in a 8-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.78–3.12 Å. In the sixth Mg site, Mg is bonded to five Si atoms to form distorted MgSi5 trigonal bipyramids that share corners with two equivalent SiMg2Si4 octahedra, edges with two equivalent SiMg2Si4 octahedra, and edges with two equivalent MgSi5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 47°. There are a spread of Mg–Si bond distances ranging from 2.71–2.85 Å. In the seventh Mg site, Mg is bonded in a 3-coordinate geometry to six Si atoms. There are a spread of Mg–Si bond distances ranging from 2.73–3.11 Å. In the eighth Mg site, Mg is bonded in a 8-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.87–2.97 Å. In the ninth Mg site, Mg is bonded in a 8-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.83–2.97 Å. In the tenth Mg site, Mg is bonded in a 8-coordinate geometry to eight Si atoms. There are a spread of Mg–Si bond distances ranging from 2.77–2.97 Å. There are twelve inequivalent Si sites. In the first Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.39 Å) and one longer (2.45 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. The Si–Si bond length is 2.37 Å. In the third Si site, Si is bonded in a 9-coordinate geometry to seven Mg and two Si atoms. There are one shorter (2.42 Å) and one longer (2.44 Å) Si–Si bond lengths. In the fourth Si site, Si is bonded in a 1-coordinate geometry to five Mg and three Si atoms. There are one shorter (2.45 Å) and one longer (2.46 Å) Si–Si bond lengths. 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 2.39 Å. In the sixth Si site, Si is bonded in a 9-coordinate geometry to six Mg and three Si atoms. There are two shorter (2.47 Å) and one longer (2.50 Å) Si–Si bond lengths. In the seventh 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 2.45–2.52 Å. In the eighth Si site, Si is bonded in a 2-coordinate geometry to three Mg and three Si atoms. There are a spread of Si–Si bond distances ranging from 2.42–2.48 Å. In the ninth Si site, Si is bonded to two equivalent Mg and four Si atoms to form distorted SiMg2Si4 octahedra that share corners with two equivalent MgSi5 trigonal bipyramids, edges with two equivalent SiMg2Si4 octahedra, and edges with two equivalent MgSi5 trigonal bipyramids. In the tenth Si site, Si is bonded in a 9-coordinate geometry to five Mg and four Si atoms. In the eleventh Si site, Si is bonded in a 9-coordinate geometry to five Mg and four Si atoms. In the twelfth Si site, Si is bonded in a 6-coordinate geometry to three Mg and three Si atoms.