Materials Data on KHfCuF7 by Materials Project
KHfCuF7 crystallizes in the orthorhombic Cmcm 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 2.72–3.24 Å. Hf4+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Hf–F bond distances ranging from 2.01–2.32 Å. Cu2+ is bonded to six F1- atoms to form distorted corner-sharing CuF6 octahedra. The corner-sharing octahedra tilt angles range from 0–44°. There are a spread of Cu–F bond distances ranging from 1.90–2.40 Å. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent Cu2+ atoms. In the second F1- site, F1- is bonded in a linear geometry to two equivalent Cu2+ atoms. In the third F1- site, F1- is bonded in a 2-coordinate geometry to two equivalent K1+, one Hf4+, and one Cu2+ atom. In the fourth F1- site, F1- is bonded in a bent 120 degrees geometry to one K1+ and two equivalent Hf4+ atoms. In the fifth F1- site, F1- is bonded in a 1-coordinate geometry to one K1+, one Hf4+, and one Cu2+ atom. In the sixth F1- site, F1- is bonded in a distorted water-like geometry to two equivalent K1+, one Hf4+, and one Cu2+ atom. In the seventh F1- site, F1- is bonded in a 1-coordinate geometry to two equivalent K1+ and two equivalent Hf4+ atoms.