DOE OSTI2020
Cs3TmO3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to four O2- atoms to form distorted CsO4 tetrahedra that share corners with five equivalent TmO4 tetrahedra and an edgeedge with one CsO4 tetrahedra. There are a spread of Cs–O bond distances ranging from 2.96–3.39 Å. In the second Cs1+ site, Cs1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Cs–O bond distances ranging from 3.05–3.30 Å. In the third 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 2.86–3.44 Å. Tm3+ is bonded to four O2- atoms to form TmO4 tetrahedra that share corners with five equivalent CsO4 tetrahedra and an edgeedge with one TmO4 tetrahedra. There are a spread of Tm–O bond distances ranging from 2.09–2.18 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to six Cs1+ and one Tm3+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three Cs1+ and two equivalent Tm3+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to four Cs1+ and one Tm3+ atom.