Materials Data on KCr2Fe3O14 by Materials Project

Abstract

KCr2Fe3O14 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. K is bonded to twelve O atoms to form KO12 cuboctahedra that share corners with six equivalent CrO4 tetrahedra and faces with six equivalent FeO6 octahedra. There are six shorter (2.78 Å) and six longer (2.94 Å) K–O bond lengths. Cr is bonded to four O atoms to form CrO4 tetrahedra that share corners with three equivalent KO12 cuboctahedra and corners with three equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 55°. There is one shorter (1.61 Å) and three longer (1.69 Å) Cr–O bond length. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra, corners with two equivalent CrO4 tetrahedra, and faces with two equivalent KO12 cuboctahedra. The corner-sharing octahedral tilt angles are 37°. There is four shorter (1.90 Å) and two longer (2.07 Å) Fe–O bond length. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cr atom. In the second O site, O is bonded in a 2-coordinate geometry to one K, one Cr, and one Fe atom. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one K and two equivalent Fe atoms.