Materials Data on KUCuSe3 by Materials Project
KUCuSe3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of K–Se bond distances ranging from 3.37–3.78 Å. U4+ is bonded to six Se2- atoms to form USe6 octahedra that share corners with two equivalent USe6 octahedra, edges with two equivalent USe6 octahedra, and edges with four equivalent CuSe4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. There are two shorter (2.84 Å) and four longer (2.85 Å) U–Se bond lengths. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with two equivalent CuSe4 tetrahedra and edges with four equivalent USe6 octahedra. There are two shorter (2.44 Å) and two longer (2.51 Å) Cu–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent K1+, two equivalent U4+, and two equivalent Cu1+ atoms. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent K1+, two equivalent U4+, and one Cu1+ atom.