Materials Data on Mg(FeO2)4 by Materials Project

Abstract

Mg(FeO2)4 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg is bonded to six equivalent O atoms to form MgO6 octahedra that share corners with six equivalent FeO6 octahedra and edges with six equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 11°. All Mg–O bond lengths are 2.15 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share edges with two equivalent MgO6 octahedra and edges with six FeO6 octahedra. There is four shorter (1.95 Å) and two longer (1.96 Å) Fe–O bond length. In the second Fe site, Fe is bonded to six equivalent O atoms to form FeO6 octahedra that share corners with six equivalent MgO6 octahedra and edges with six equivalent FeO6 octahedra. The corner-sharing octahedral tilt angles are 11°. All Fe–O bond lengths are 2.06 Å. There are two inequivalent O sites. In the first O site, O is bonded in a rectangular see-saw-like geometry to one Mg and three Fe atoms. In the second O site, O is bonded in a distorted T-shaped geometry to three equivalent Fe atoms.