Materials Data on CsLa2CuSe4 by Materials Project
CsLa2CuSe4 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 3.55–4.05 Å. La3+ is bonded to six Se2- atoms to form LaSe6 octahedra that share corners with three equivalent LaSe6 octahedra, a cornercorner with one CuSe4 tetrahedra, edges with five equivalent LaSe6 octahedra, and edges with two equivalent CuSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 0–33°. There are a spread of La–Se bond distances ranging from 2.94–3.12 Å. Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with two equivalent LaSe6 octahedra, corners with two equivalent CuSe4 tetrahedra, and edges with four equivalent LaSe6 octahedra. The corner-sharing octahedral tilt angles are 3°. There are two shorter (2.50 Å) and two longer (2.53 Å) Cu–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Cs1+, three equivalent La3+, and one Cu1+ atom to form a mixture of distorted face, edge, and corner-sharing SeCs2La3Cu octahedra. The corner-sharing octahedra tilt angles range from 3–69°. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent Cs1+, two equivalent La3+, and two equivalent Cu1+ atoms. In the third Se2- site, Se2- is bonded to two equivalent Cs1+ and four equivalent La3+ atoms to form a mixture of distorted edge and corner-sharing SeCs2La4 octahedra. The corner-sharing octahedra tilt angles range from 3–46°.