DOE OSTI2020
Cs2PbO2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Cs–O bond distances ranging from 2.93–3.04 Å. In the second Cs1+ site, Cs1+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Cs–O bond distances ranging from 3.00–3.32 Å. In the third Cs1+ site, Cs1+ is bonded to five O2- atoms to form distorted edge-sharing CsO5 square pyramids. There are a spread of Cs–O bond distances ranging from 3.02–3.22 Å. In the fourth Cs1+ site, Cs1+ is bonded to five O2- atoms to form distorted edge-sharing CsO5 trigonal bipyramids. There are a spread of Cs–O bond distances ranging from 2.96–3.30 Å. There are two inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Pb–O bond distances ranging from 2.15–2.31 Å. In the second Pb2+ site, Pb2+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of Pb–O bond distances ranging from 2.16–2.29 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Cs1+ and two equivalent Pb2+ atoms to form distorted OCs4Pb2 octahedra that share corners with three equivalent OCs3Pb2 trigonal bipyramids and edges with eight OCs4Pb2 octahedra. In the second O2- site, O2- is bonded to five Cs1+ and one Pb2+ atom to form distorted OCs5Pb octahedra that share corners with three equivalent OCs5Pb octahedra, edges with four OCs4Pb2 octahedra, and edges with three equivalent OCs3Pb2 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 16–20°. In the third O2- site, O2- is bonded to five Cs1+ and one Pb2+ atom to form distorted OCs5Pb octahedra that share corners with three equivalent OCs5Pb octahedra, a cornercorner with one OCs3Pb2 trigonal bipyramid, edges with seven OCs4Pb2 octahedra, and an edgeedge with one OCs3Pb2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 16–20°. In the fourth O2- site, O2- is bonded to three Cs1+ and two equivalent Pb2+ atoms to form distorted OCs3Pb2 trigonal bipyramids that share corners with four OCs4Pb2 octahedra, edges with four OCs5Pb octahedra, and an edgeedge with one OCs3Pb2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 30–79°.