Materials Data on K3NaFeCl6 by Materials Project

K3NaFeCl6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to five Cl1- atoms to form distorted KCl5 trigonal bipyramids that share corners with two equivalent KCl6 octahedra, edges with two equivalent KCl6 octahedra, and edges with two equivalent KCl5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 12–83°. There are a spread of K–Cl bond distances ranging from 2.90–3.51 Å. In the second K1+ site, K1+ is bonded to six Cl1- atoms to form distorted KCl6 octahedra that share corners with four equivalent KCl5 trigonal bipyramids, edges with two equivalent KCl6 octahedra, and edges with four equivalent KCl5 trigonal bipyramids. There are a spread of K–Cl bond distances ranging from 3.03–3.37 Å. Na1+ is bonded in a distorted rectangular see-saw-like geometry to six Cl1- atoms. There are a spread of Na–Cl bond distances ranging from 2.64–3.50 Å. Fe2+ is bonded in a square co-planar geometry to four equivalent Cl1- atoms. There are two shorter (2.39 Å) and two longer (2.42 Å) Fe–Cl bond lengths. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted see-saw-like geometry to four K1+ atoms. In the second Cl1- site, Cl1- is bonded to three K1+ and two equivalent Na1+ atoms to form a mixture of distorted edge, corner, and face-sharing ClK3Na2 trigonal bipyramids. In the third Cl1- site, Cl1- is bonded in a 2-coordinate geometry to one K1+, one Na1+, and two equivalent Fe2+ atoms.