Materials Data on Li2UN2 by Materials Project

Abstract

Li2UN2 crystallizes in the trigonal P-3 space group. The structure is three-dimensional. Li1+ is bonded to four equivalent N3- atoms to form distorted LiN4 tetrahedra that share corners with six UN6 octahedra, corners with six equivalent LiN4 tetrahedra, edges with three UN6 octahedra, and edges with three equivalent LiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 5–61°. There are a spread of Li–N bond distances ranging from 2.11–2.29 Å. There are two inequivalent U4+ sites. In the first U4+ site, U4+ is bonded to six equivalent N3- atoms to form UN6 octahedra that share corners with twelve equivalent LiN4 tetrahedra, edges with six equivalent UN6 octahedra, and edges with six equivalent LiN4 tetrahedra. All U–N bond lengths are 2.37 Å. In the second U4+ site, U4+ is bonded to six equivalent N3- atoms to form UN6 octahedra that share corners with twelve equivalent LiN4 tetrahedra, edges with six UN6 octahedra, and edges with six equivalent LiN4 tetrahedra. There are three shorter (2.35 Å) and three longer (2.39 Å) U–N bond lengths. N3- is bonded to four equivalent Li1+ and three U4+ atoms to form a mixture of distorted edge and corner-sharing NLi4U3 pentagonal bipyramids.