DOE OSTI2020
CsPb2Cl5 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. Cs1+ is bonded in a 10-coordinate geometry to ten Cl1- atoms. There are eight shorter (3.70 Å) and two longer (3.83 Å) Cs–Cl bond lengths. Pb2+ is bonded in a 8-coordinate geometry to eight Cl1- atoms. There are a spread of Pb–Cl bond distances ranging from 2.78–3.27 Å. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded to two equivalent Cs1+ and four equivalent Pb2+ atoms to form distorted ClCs2Pb4 octahedra that share corners with six equivalent ClCs2Pb4 octahedra, corners with sixteen equivalent ClCs2Pb3 square pyramids, and faces with eight equivalent ClCs2Pb3 square pyramids. The corner-sharing octahedra tilt angles range from 0–36°. In the second Cl1- site, Cl1- is bonded to two equivalent Cs1+ and three equivalent Pb2+ atoms to form distorted ClCs2Pb3 square pyramids that share corners with four equivalent ClCs2Pb4 octahedra, corners with twelve equivalent ClCs2Pb3 square pyramids, edges with seven equivalent ClCs2Pb3 square pyramids, faces with two equivalent ClCs2Pb4 octahedra, and a faceface with one ClCs2Pb3 square pyramid. The corner-sharing octahedra tilt angles range from 45–58°.