Materials Data on U3Cu2Se7 by Materials Project
Cu2U3Se7 crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. U4+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of U–Se bond distances ranging from 2.79–3.23 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded in a tetrahedral geometry to four Se2- atoms. There are three shorter (2.39 Å) and one longer (2.42 Å) Cu–Se bond lengths. In the second Cu1+ site, Cu1+ is bonded in a trigonal planar geometry to three equivalent Se2- atoms. All Cu–Se bond lengths are 2.34 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent U4+ and one Cu1+ atom. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to four equivalent U4+ and one Cu1+ atom. In the third Se2- site, Se2- is bonded in a distorted tetrahedral geometry to three equivalent U4+ and one Cu1+ atom.