Materials Data on K2BiF5 by Materials Project

Abstract

K2BiF5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. K1+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of K–F bond distances ranging from 2.72–2.98 Å. Bi3+ is bonded to seven F1- atoms to form edge-sharing BiF7 pentagonal bipyramids. There are a spread of Bi–F bond distances ranging from 2.24–2.52 Å. There are four inequivalent F1- sites. In the first F1- site, F1- is bonded to four equivalent K1+ and one Bi3+ atom to form distorted corner-sharing FK4Bi square pyramids. In the second F1- site, F1- is bonded in a distorted rectangular see-saw-like geometry to two equivalent K1+ and two equivalent Bi3+ atoms. In the third F1- site, F1- is bonded in a 5-coordinate geometry to four equivalent K1+ and one Bi3+ atom. In the fourth F1- site, F1- is bonded in a 5-coordinate geometry to four equivalent K1+ and one Bi3+ atom.