Materials Data on KNbF6 by Materials Project
KNbF6 crystallizes in the tetragonal P4_2/mcm space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are four shorter (2.69 Å) and four longer (3.14 Å) K–F bond lengths. Nb5+ is bonded in an octahedral geometry to six F1- atoms. All Nb–F bond lengths are 1.94 Å. There are two inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to two equivalent K1+ and one Nb5+ atom. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to one K1+ and one Nb5+ atom.