Materials Data on K2NbF7 by Materials Project
K2NbF7 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.70–3.01 Å. In the second K1+ site, K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.69–2.97 Å. Nb5+ is bonded in a distorted pentagonal bipyramidal geometry to seven F1- atoms. There are a spread of Nb–F bond distances ranging from 1.97–2.02 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a 4-coordinate geometry to three K1+ and one Nb5+ atom. In the second F1- site, F1- is bonded in a 1-coordinate geometry to three K1+ and one Nb5+ atom. In the third F1- site, F1- is bonded in a 3-coordinate geometry to two K1+ and one Nb5+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to two K1+ and one Nb5+ atom. In the fifth F1- site, F1- is bonded in a distorted single-bond geometry to two K1+ and one Nb5+ atom. In the sixth F1- site, F1- is bonded in a 4-coordinate geometry to three K1+ and one Nb5+ atom. In the seventh F1- site, F1- is bonded in a 1-coordinate geometry to three K1+ and one Nb5+ atom.