Materials Data on K3FeF3 by Materials Project
K3FeF3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent K sites. In the first K site, K is bonded in a 6-coordinate geometry to six F atoms. There are a spread of K–F bond distances ranging from 2.76–3.21 Å. In the second K site, K is bonded in a 5-coordinate geometry to five F atoms. There are a spread of K–F bond distances ranging from 2.68–3.15 Å. In the third K site, K is bonded in a T-shaped geometry to three F atoms. There are a spread of K–F bond distances ranging from 2.51–2.60 Å. In the fourth K site, K is bonded in a T-shaped geometry to three F atoms. There are a spread of K–F bond distances ranging from 2.52–2.62 Å. In the fifth K site, K is bonded in a 6-coordinate geometry to six F atoms. There are a spread of K–F bond distances ranging from 2.79–3.22 Å. In the sixth K site, K is bonded in a 5-coordinate geometry to five F atoms. There are a spread of K–F bond distances ranging from 2.80–3.12 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a T-shaped geometry to three F atoms. There are two shorter (2.13 Å) and one longer (2.14 Å) Fe–F bond lengths. In the second Fe site, Fe is bonded in a T-shaped geometry to three F atoms. There are two shorter (2.13 Å) and one longer (2.18 Å) Fe–F bond lengths. There are six inequivalent F sites. In the first F site, F is bonded in a 6-coordinate geometry to five K and one Fe atom. In the second F site, F is bonded to five K and one Fe atom to form a mixture of distorted edge and corner-sharing FK5Fe octahedra. The corner-sharing octahedra tilt angles range from 5–6°. In the third F site, F is bonded in a 5-coordinate geometry to four K and one Fe atom. In the fourth F site, F is bonded in a 6-coordinate geometry to five K and one Fe atom. In the fifth F site, F is bonded in a 5-coordinate geometry to four K and one Fe atom. In the sixth F site, F is bonded to five K and one Fe atom to form a mixture of distorted edge and corner-sharing FK5Fe octahedra. The corner-sharing octahedra tilt angles range from 6–15°.