Materials Data on K2CuF4 by Materials Project

Abstract

K2CuF4 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.68–3.09 Å. Cu2+ is bonded to six F1- atoms to form corner-sharing CuF6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.96 Å) and two longer (2.22 Å) Cu–F bond lengths. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded to four equivalent K1+ and two equivalent Cu2+ atoms to form a mixture of corner and edge-sharing FK4Cu2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second F1- site, F1- is bonded in a distorted linear geometry to four equivalent K1+ and two equivalent Cu2+ atoms. In the third F1- site, F1- is bonded in a distorted single-bond geometry to six equivalent K1+ and one Cu2+ atom.