Materials Data on Si3N4 by Materials Project

Abstract

Si3N4 crystallizes in the hexagonal P6_3/m space group. The structure is one-dimensional and consists of one Si3N4 ribbon oriented in the (0, 0, 1) direction. there are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four N3- atoms to form a mixture of corner and edge-sharing SiN4 trigonal pyramids. There are a spread of Si–N bond distances ranging from 1.69–1.89 Å. In the second Si4+ site, Si4+ is bonded to four N3- atoms to form a mixture of corner and edge-sharing SiN4 trigonal pyramids. There are a spread of Si–N bond distances ranging from 1.69–1.79 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in an L-shaped geometry to two equivalent Si4+ atoms. In the second N3- site, N3- is bonded in a rectangular see-saw-like geometry to four Si4+ atoms. In the third N3- site, N3- is bonded in a distorted trigonal planar geometry to three Si4+ atoms.