DOE OSTI2020
Cs2CeO3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to seven O2- atoms to form distorted CsO7 pentagonal bipyramids that share corners with two equivalent CsO7 pentagonal bipyramids, a cornercorner with one CeO4 tetrahedra, and edges with four CeO4 tetrahedra. There are a spread of Cs–O bond distances ranging from 3.02–3.52 Å. In the second Cs1+ site, Cs1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Cs–O bond distances ranging from 3.06–3.53 Å. In the third Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Cs–O bond distances ranging from 2.97–3.52 Å. In the fourth Cs1+ site, Cs1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Cs–O bond distances ranging from 3.09–3.52 Å. In the fifth Cs1+ site, Cs1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Cs–O bond distances ranging from 3.03–3.55 Å. In the sixth Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Cs–O bond distances ranging from 2.96–3.55 Å. In the seventh Cs1+ site, Cs1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Cs–O bond distances ranging from 3.12–3.49 Å. In the eighth Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Cs–O bond distances ranging from 2.97–3.52 Å. There are four inequivalent Ce4+ sites. In the first Ce4+ site, Ce4+ is bonded to four O2- atoms to form CeO4 tetrahedra that share corners with two equivalent CeO4 tetrahedra and an edgeedge with one CsO7 pentagonal bipyramid. There are a spread of Ce–O bond distances ranging from 2.04–2.21 Å. In the second Ce4+ site, Ce4+ is bonded to four O2- atoms to form CeO4 tetrahedra that share corners with two equivalent CeO4 tetrahedra and an edgeedge with one CsO7 pentagonal bipyramid. There are a spread of Ce–O bond distances ranging from 2.04–2.21 Å. In the third Ce4+ site, Ce4+ is bonded to four O2- atoms to form corner-sharing CeO4 tetrahedra. There are a spread of Ce–O bond distances ranging from 2.04–2.22 Å. In the fourth Ce4+ site, Ce4+ is bonded to four O2- atoms to form CeO4 tetrahedra that share a cornercorner with one CsO7 pentagonal bipyramid, corners with two equivalent CeO4 tetrahedra, and edges with two equivalent CsO7 pentagonal bipyramids. There are a spread of Ce–O bond distances ranging from 2.04–2.21 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Cs1+ and two Ce4+ atoms. In the second O2- site, O2- is bonded in a 1-coordinate geometry to five Cs1+ and one Ce4+ atom. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Cs1+ and one Ce4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to five Cs1+ and one Ce4+ atom. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to five Cs1+ and one Ce4+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Cs1+ and two Ce4+ atoms. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to two Cs1+ and two Ce4+ atoms. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to five Cs1+ and one Ce4+ atom. In the ninth O2- site, O2- is bonded in a 6-coordinate geometry to five Cs1+ and one Ce4+ atom. In the tenth O2- site, O2- is bonded in a 6-coordinate geometry to five Cs1+ and one Ce4+ atom. In the eleventh O2- site, O2- is bonded in a distorted single-bond geometry to five Cs1+ and one Ce4+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to two Cs1+ and two Ce4+ atoms.