Materials Data on CeU4N5 by Materials Project

Abstract

U4CeN5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent U3+ sites. In the first U3+ site, U3+ is bonded to six N3- atoms to form UN6 octahedra that share corners with three equivalent UN6 octahedra, corners with three equivalent CeN6 octahedra, edges with three equivalent CeN6 octahedra, and edges with nine UN6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are three shorter (2.38 Å) and three longer (2.43 Å) U–N bond lengths. In the second U3+ site, U3+ is bonded to six N3- atoms to form a mixture of edge and corner-sharing UN6 octahedra. The corner-sharing octahedral tilt angles are 0°. All U–N bond lengths are 2.44 Å. Ce3+ is bonded to six equivalent N3- atoms to form CeN6 octahedra that share corners with six equivalent UN6 octahedra, edges with six equivalent UN6 octahedra, and edges with six equivalent CeN6 octahedra. The corner-sharing octahedral tilt angles are 6°. All Ce–N bond lengths are 2.56 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded to three equivalent U3+ and three equivalent Ce3+ atoms to form a mixture of edge and corner-sharing NCe3U3 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second N3- site, N3- is bonded to six equivalent U3+ atoms to form a mixture of edge and corner-sharing NU6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third N3- site, N3- is bonded to six U3+ atoms to form a mixture of edge and corner-sharing NU6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.