Materials Data on Nb4WC5 by Materials Project

Abstract

Nb4WC5 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Nb+4.50+ sites. In the first Nb+4.50+ site, Nb+4.50+ is bonded to six C4- atoms to form NbC6 octahedra that share corners with three equivalent NbC6 octahedra, corners with three equivalent WC6 octahedra, edges with three equivalent WC6 octahedra, and edges with nine NbC6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are three shorter (2.24 Å) and three longer (2.26 Å) Nb–C bond lengths. In the second Nb+4.50+ site, Nb+4.50+ is bonded to six C4- atoms to form a mixture of corner and edge-sharing NbC6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are three shorter (2.24 Å) and three longer (2.25 Å) Nb–C bond lengths. W2+ is bonded to six equivalent C4- atoms to form WC6 octahedra that share corners with six equivalent NbC6 octahedra, edges with six equivalent NbC6 octahedra, and edges with six equivalent WC6 octahedra. The corner-sharing octahedral tilt angles are 2°. All W–C bond lengths are 2.20 Å. There are three inequivalent C4- sites. In the first C4- site, C4- is bonded to six Nb+4.50+ atoms to form a mixture of corner and edge-sharing CNb6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second C4- site, C4- is bonded to six equivalent Nb+4.50+ atoms to form a mixture of corner and edge-sharing CNb6 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third C4- site, C4- is bonded to three equivalent Nb+4.50+ and three equivalent W2+ atoms to form a mixture of corner and edge-sharing CNb3W3 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.