DOE OSTI2020
Cs6Bi4O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are six inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Cs–O bond distances ranging from 2.99–3.68 Å. In the second Cs1+ site, Cs1+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Cs–O bond distances ranging from 3.11–3.73 Å. In the third 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 2.87–3.23 Å. In the fourth Cs1+ site, Cs1+ is bonded to six O2- atoms to form distorted CsO6 pentagonal pyramids that share a cornercorner with one CsO5 trigonal bipyramid, an edgeedge with one CsO6 pentagonal pyramid, and a faceface with one CsO5 trigonal bipyramid. There are a spread of Cs–O bond distances ranging from 3.09–3.30 Å. In the fifth Cs1+ site, Cs1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Cs–O bond distances ranging from 3.04–3.38 Å. In the sixth Cs1+ site, Cs1+ is bonded to five O2- atoms to form a mixture of distorted corner and face-sharing CsO5 trigonal bipyramids. There are a spread of Cs–O bond distances ranging from 3.02–3.53 Å. There are four inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded in a distorted see-saw-like geometry to four O2- atoms. There are a spread of Bi–O bond distances ranging from 2.06–2.54 Å. In the second Bi3+ site, Bi3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.05–2.16 Å. In the third Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Bi–O bond distances ranging from 2.06–2.86 Å. In the fourth Bi3+ site, Bi3+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Bi–O bond distances ranging from 2.06–2.21 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to four Cs1+ and one Bi3+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to five Cs1+ and one Bi3+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to four Cs1+ and one Bi3+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to five Cs1+ and one Bi3+ atom. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to three Cs1+ and three Bi3+ atoms. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to five Cs1+ and one Bi3+ atom. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to three Cs1+ and two Bi3+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to three Cs1+ and two Bi3+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to two Cs1+ and two Bi3+ atoms.