Materials Data on KNa3Mg4F12 by Materials Project

Abstract

KNa3Mg4F12 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. K1+ is bonded in a 12-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.56–2.99 Å. There are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.40–2.79 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.38–2.67 Å. In the third Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Na–F bond distances ranging from 2.37–2.75 Å. There are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 16–28°. There are a spread of Mg–F bond distances ranging from 1.99–2.04 Å. In the second Mg2+ site, Mg2+ is bonded to six F1- atoms to form corner-sharing MgF6 octahedra. The corner-sharing octahedra tilt angles range from 18–28°. There are a spread of Mg–F bond distances ranging from 1.98–2.05 Å. There are eight inequivalent F1- sites. In the first F1- site, F1- is bonded in a 5-coordinate geometry to one K1+, two Na1+, and two Mg2+ atoms. In the second F1- site, F1- is bonded in a 5-coordinate geometry to one K1+, two Na1+, and two Mg2+ atoms. In the third F1- site, F1- is bonded in a 5-coordinate geometry to three Na1+ and two Mg2+ atoms. In the fourth F1- site, F1- is bonded in a 5-coordinate geometry to one K1+, two Na1+, and two Mg2+ atoms. In the fifth F1- site, F1- is bonded in a 5-coordinate geometry to two equivalent K1+, one Na1+, and two equivalent Mg2+ atoms. In the sixth F1- site, F1- is bonded in a 4-coordinate geometry to two equivalent K1+, one Na1+, and two equivalent Mg2+ atoms. In the seventh F1- site, F1- is bonded in a 4-coordinate geometry to two Na1+ and two equivalent Mg2+ atoms. In the eighth F1- site, F1- is bonded in a distorted tetrahedral geometry to two Na1+ and two equivalent Mg2+ atoms.