Materials Data on Cr3N2 by Materials Project

Abstract

Cr3N2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Cr2+ sites. In the first Cr2+ site, Cr2+ is bonded to four equivalent N3- atoms to form distorted CrN4 tetrahedra that share corners with six equivalent CrN6 octahedra, corners with six equivalent CrN4 tetrahedra, edges with three equivalent CrN6 octahedra, and edges with three equivalent CrN4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–51°. There are three shorter (1.87 Å) and one longer (2.34 Å) Cr–N bond lengths. In the second Cr2+ site, Cr2+ is bonded to six equivalent N3- atoms to form CrN6 octahedra that share corners with twelve equivalent CrN4 tetrahedra, edges with six equivalent CrN6 octahedra, and edges with six equivalent CrN4 tetrahedra. There are two shorter (2.30 Å) and four longer (2.35 Å) Cr–N bond lengths. N3- is bonded in a 3-coordinate geometry to seven Cr2+ atoms.