Materials Data on Ba4Mg(SiN3)2 by Materials Project
Ba4Mg(SiN3)2 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 4-coordinate geometry to eight N3- atoms. There are a spread of Ba–N bond distances ranging from 2.86–3.36 Å. In the second Ba2+ site, Ba2+ is bonded in a 6-coordinate geometry to six N3- atoms. There are a spread of Ba–N bond distances ranging from 2.67–3.03 Å. Mg2+ is bonded in a square co-planar geometry to four equivalent N3- atoms. All Mg–N bond lengths are 2.19 Å. Si4+ is bonded to four N3- atoms to form edge-sharing SiN4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.82 Å) Si–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a distorted L-shaped geometry to six Ba2+ and two equivalent Si4+ atoms. In the second N3- site, N3- is bonded to four Ba2+, one Mg2+, and one Si4+ atom to form a mixture of distorted edge and corner-sharing NBa4MgSi octahedra. The corner-sharing octahedra tilt angles range from 3–72°.