Materials Data on Mg3Si9B36C by Materials Project

Abstract

Mg3B36Si9C crystallizes in the trigonal R3m space group. The structure is three-dimensional and consists of six silicon molecules and one Mg3B36Si7C framework. In the Mg3B36Si7C framework, Mg2+ is bonded in a 8-coordinate geometry to eight B+0.83- atoms. There are a spread of Mg–B bond distances ranging from 2.72–2.83 Å. There are eight inequivalent B+0.83- sites. In the first B+0.83- site, B+0.83- is bonded in a 1-coordinate geometry to five B+0.83- and one Si+3.11+ atom. There are a spread of B–B bond distances ranging from 1.75–1.81 Å. The B–Si bond length is 2.04 Å. In the second B+0.83- site, B+0.83- is bonded in a 1-coordinate geometry to five B+0.83- and one Si+3.11+ atom. There is two shorter (1.75 Å) and two longer (1.82 Å) B–B bond length. The B–Si bond length is 1.95 Å. In the third B+0.83- site, B+0.83- is bonded in a 1-coordinate geometry to five B+0.83- and one Si+3.11+ atom. There are a spread of B–B bond distances ranging from 1.79–1.86 Å. The B–Si bond length is 2.05 Å. In the fourth B+0.83- site, B+0.83- is bonded in a single-bond geometry to five B+0.83- and one C4- atom. There is two shorter (1.80 Å) and two longer (1.81 Å) B–B bond length. The B–C bond length is 1.62 Å. In the fifth B+0.83- site, B+0.83- is bonded in a 7-coordinate geometry to one Mg2+ and six B+0.83- atoms. There are a spread of B–B bond distances ranging from 1.78–1.82 Å. In the sixth B+0.83- site, B+0.83- is bonded in a 7-coordinate geometry to one Mg2+ and six B+0.83- atoms. There are a spread of B–B bond distances ranging from 1.72–1.82 Å. In the seventh B+0.83- site, B+0.83- is bonded in a 1-coordinate geometry to one Mg2+, five B+0.83-, and one Si+3.11+ atom. The B–B bond length is 1.77 Å. The B–Si bond length is 2.06 Å. In the eighth B+0.83- site, B+0.83- is bonded in a 1-coordinate geometry to one Mg2+, five B+0.83-, and one Si+3.11+ atom. The B–Si bond length is 2.04 Å. There are three inequivalent Si+3.11+ sites. In the first Si+3.11+ site, Si+3.11+ is bonded in a trigonal non-coplanar geometry to three B+0.83- atoms. In the second Si+3.11+ site, Si+3.11+ is bonded in a trigonal non-coplanar geometry to three B+0.83- atoms. In the third Si+3.11+ site, Si+3.11+ is bonded in a distorted tetrahedral geometry to three equivalent B+0.83- and one C4- atom. The Si–C bond length is 1.84 Å. C4- is bonded in a tetrahedral geometry to three equivalent B+0.83- and one Si+3.11+ atom.