Materials Data on KNaSiF6 by Materials Project
KNaSiF6 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of K–F bond distances ranging from 2.69–3.15 Å. Na1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Na–F bond distances ranging from 2.31–2.82 Å. Si4+ is bonded in an octahedral geometry to six F1- atoms. There are a spread of Si–F bond distances ranging from 1.71–1.74 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent K1+, one Na1+, and one Si4+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one K1+, two equivalent Na1+, and one Si4+ atom. In the third F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+, one Na1+, and one Si4+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to one K1+, three equivalent Na1+, and one Si4+ atom.