DOE OSTI2020
Cs3TmO3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 1-coordinate geometry to five O2- atoms. There are a spread of Cs–O bond distances ranging from 2.84–3.37 Å. In the second Cs1+ site, Cs1+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. There are two shorter (2.96 Å) and two longer (3.40 Å) Cs–O bond lengths. In the third Cs1+ site, Cs1+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. There are two shorter (3.12 Å) and two longer (3.25 Å) Cs–O bond lengths. Tm3+ is bonded to four O2- atoms to form edge-sharing TmO4 tetrahedra. There are a spread of Tm–O bond distances ranging from 2.10–2.17 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Cs1+ and two equivalent Tm3+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to six Cs1+ and one Tm3+ atom.