Materials Data on CsNd2CuSe4 by Materials Project
CsNd2CuSe4 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 3.48–4.02 Å. Nd3+ is bonded to six Se2- atoms to form NdSe6 octahedra that share corners with three equivalent NdSe6 octahedra, a cornercorner with one CuSe4 tetrahedra, edges with five equivalent NdSe6 octahedra, and edges with two equivalent CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–34°. There are a spread of Nd–Se bond distances ranging from 2.91–3.07 Å. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with two equivalent NdSe6 octahedra, corners with two equivalent CuSe4 tetrahedra, and edges with four equivalent NdSe6 octahedra. The corner-sharing octahedral tilt angles are 3°. All Cu–Se bond lengths are 2.50 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Cs1+, three equivalent Nd3+, and one Cu1+ atom to form a mixture of distorted edge, face, and corner-sharing SeCs2Nd3Cu octahedra. The corner-sharing octahedra tilt angles range from 3–68°. In the second Se2- site, Se2- is bonded to two equivalent Cs1+ and four equivalent Nd3+ atoms to form a mixture of distorted edge and corner-sharing SeCs2Nd4 octahedra. The corner-sharing octahedra tilt angles range from 3–47°. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent Cs1+, two equivalent Nd3+, and two equivalent Cu1+ atoms.