DOE OSTI2020
Cs2ZrCu3F12 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Cs–F bond distances ranging from 3.01–3.30 Å. In the second Cs1+ site, Cs1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Cs–F bond distances ranging from 3.06–3.46 Å. Zr4+ is bonded to seven F1- atoms to form ZrF7 pentagonal bipyramids that share corners with four CuF6 octahedra and edges with two equivalent CuF6 octahedra. The corner-sharing octahedra tilt angles range from 40–53°. There are a spread of Zr–F bond distances ranging from 2.04–2.33 Å. There are three inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded to six F1- atoms to form CuF6 octahedra that share corners with four CuF6 octahedra and corners with two equivalent ZrF7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 38–43°. There are a spread of Cu–F bond distances ranging from 1.94–2.43 Å. In the second Cu2+ site, Cu2+ is bonded to six F1- atoms to form CuF6 octahedra that share corners with four CuF6 octahedra and edges with two equivalent ZrF7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 43–52°. There are a spread of Cu–F bond distances ranging from 1.94–2.23 Å. In the third Cu2+ site, Cu2+ is bonded to six F1- atoms to form CuF6 octahedra that share corners with four CuF6 octahedra and corners with two equivalent ZrF7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 38–40°. There are a spread of Cu–F bond distances ranging from 1.93–2.33 Å. There are eight inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent Cs1+, one Zr4+, and one Cu2+ atom. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two Cu2+ atoms. In the third F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Cs1+ and two Cu2+ atoms. In the fourth F1- site, F1- is bonded in a 2-coordinate geometry to one Cs1+, one Zr4+, and one Cu2+ atom. In the fifth F1- site, F1- is bonded in a 1-coordinate geometry to one Cs1+, one Zr4+, and one Cu2+ atom. In the sixth F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to one Zr4+ and two equivalent Cu2+ atoms. In the seventh F1- site, F1- is bonded in a 4-coordinate geometry to two Cs1+, one Zr4+, and one Cu2+ atom. In the eighth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one Cs1+ and two equivalent Cu2+ atoms.