Materials Data on YbCuSe2 by Materials Project
YbCuSe2 crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. Yb3+ is bonded to six Se2- atoms to form YbSe6 octahedra that share corners with six equivalent CuSe4 tetrahedra, edges with six equivalent YbSe6 octahedra, and edges with three equivalent CuSe4 tetrahedra. There are three shorter (2.86 Å) and three longer (2.98 Å) Yb–Se bond lengths. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with six equivalent YbSe6 octahedra, corners with six equivalent CuSe4 tetrahedra, and edges with three equivalent YbSe6 octahedra. The corner-sharing octahedra tilt angles range from 20–55°. There are one shorter (2.36 Å) and three longer (2.47 Å) Cu–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three equivalent Yb3+ and one Cu1+ atom. In the second Se2- site, Se2- is bonded to three equivalent Yb3+ and three equivalent Cu1+ atoms to form distorted edge-sharing SeYb3Cu3 octahedra.