Materials Data on NaCu3Te2 by Materials Project

Abstract

NaCu3Te2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Na1+ is bonded to six equivalent Te2- atoms to form NaTe6 octahedra that share corners with six equivalent CuCu6Te6 cuboctahedra, corners with eighteen equivalent CuCu3Te4 tetrahedra, edges with six equivalent CuCu6Te6 cuboctahedra, edges with six equivalent NaTe6 octahedra, and faces with two equivalent CuCu3Te4 tetrahedra. All Na–Te bond lengths are 3.21 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to six equivalent Cu1+ and six equivalent Te2- atoms to form distorted CuCu6Te6 cuboctahedra that share corners with six equivalent NaTe6 octahedra, corners with six equivalent CuCu3Te4 tetrahedra, edges with six equivalent NaTe6 octahedra, faces with six equivalent CuCu6Te6 cuboctahedra, and faces with six equivalent CuCu3Te4 tetrahedra. The corner-sharing octahedral tilt angles are 2°. All Cu–Cu bond lengths are 2.60 Å. All Cu–Te bond lengths are 3.11 Å. In the second Cu1+ site, Cu1+ is bonded to three equivalent Cu1+ and four equivalent Te2- atoms to form distorted CuCu3Te4 tetrahedra that share corners with three equivalent CuCu6Te6 cuboctahedra, corners with nine equivalent NaTe6 octahedra, corners with three equivalent CuCu3Te4 tetrahedra, edges with six equivalent CuCu3Te4 tetrahedra, faces with three equivalent CuCu6Te6 cuboctahedra, a faceface with one NaTe6 octahedra, and faces with three equivalent CuCu3Te4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–52°. All Cu–Te bond lengths are 2.70 Å. Te2- is bonded in a 10-coordinate geometry to three equivalent Na1+ and seven Cu1+ atoms.