Materials Data on KCeF4 by Materials Project
KCeF4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K1+ is bonded in a 7-coordinate geometry to seven F1- atoms. There are a spread of K–F bond distances ranging from 2.64–2.79 Å. Ce3+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Ce–F bond distances ranging from 2.34–2.55 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted trigonal non-coplanar geometry to three equivalent Ce3+ atoms. In the second F1- site, F1- is bonded to one K1+ and three equivalent Ce3+ atoms to form a mixture of edge and corner-sharing FKCe3 tetrahedra. In the third F1- site, F1- is bonded to two equivalent K1+ and two equivalent Ce3+ atoms to form distorted FK2Ce2 tetrahedra that share corners with ten FK2Ce2 tetrahedra and an edgeedge with one FKCe3 tetrahedra. In the fourth F1- site, F1- is bonded in a 5-coordinate geometry to four equivalent K1+ and one Ce3+ atom.