Materials Data on Sr(Si3N4)2 by Materials Project
Sr(Si3N4)2 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Sr2+ is bonded in a 10-coordinate geometry to ten N+2.25- atoms. There are a spread of Sr–N bond distances ranging from 2.70–3.20 Å. There are two inequivalent Si+2.67+ sites. In the first Si+2.67+ site, Si+2.67+ is bonded to four N+2.25- atoms to form corner-sharing SiN4 tetrahedra. There are a spread of Si–N bond distances ranging from 1.69–1.78 Å. In the second Si+2.67+ site, Si+2.67+ is bonded in a trigonal non-coplanar geometry to three N+2.25- atoms. There is two shorter (1.75 Å) and one longer (1.76 Å) Si–N bond length. There are three inequivalent N+2.25- sites. In the first N+2.25- site, N+2.25- is bonded in a 2-coordinate geometry to two equivalent Sr2+ and two equivalent Si+2.67+ atoms. In the second N+2.25- site, N+2.25- is bonded in a trigonal planar geometry to one Sr2+ and three Si+2.67+ atoms. In the third N+2.25- site, N+2.25- is bonded in a distorted trigonal non-coplanar geometry to one Sr2+ and three Si+2.67+ atoms.