Materials Data on CsSm2CuSe4 by Materials Project

Abstract

CsSm2CuSe4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Cs1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.47–4.00 Å. Sm3+ is bonded to six Se2- atoms to form SmSe6 octahedra that share corners with three equivalent SmSe6 octahedra, a cornercorner with one CuSe4 tetrahedra, edges with five equivalent SmSe6 octahedra, and edges with two equivalent CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–34°. There are a spread of Sm–Se bond distances ranging from 2.88–3.05 Å. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with two equivalent SmSe6 octahedra, corners with two equivalent CuSe4 tetrahedra, and edges with four equivalent SmSe6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Cu–Se bond lengths are 2.49 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent Cs1+, two equivalent Sm3+, and two equivalent Cu1+ atoms. In the second Se2- site, Se2- is bonded to two equivalent Cs1+, three equivalent Sm3+, and one Cu1+ atom to form a mixture of distorted edge, corner, and face-sharing SeCs2Sm3Cu octahedra. The corner-sharing octahedra tilt angles range from 4–68°. In the third Se2- site, Se2- is bonded to two equivalent Cs1+ and four equivalent Sm3+ atoms to form a mixture of distorted edge and corner-sharing SeCs2Sm4 octahedra. The corner-sharing octahedra tilt angles range from 4–47°.