Materials Data on Na(FeO2)2 by Materials Project

Abstract

Na(FeO2)2 is Spinel structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na is bonded to four O atoms to form NaO4 tetrahedra that share corners with twelve FeO6 octahedra. The corner-sharing octahedra tilt angles range from 57–65°. There are two shorter (2.14 Å) and two longer (2.18 Å) Na–O bond lengths. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent NaO4 tetrahedra and edges with six FeO6 octahedra. There are four shorter (2.06 Å) and two longer (2.08 Å) Fe–O bond lengths. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent NaO4 tetrahedra and edges with six FeO6 octahedra. There is two shorter (1.92 Å) and four longer (1.98 Å) Fe–O bond length. In the third Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent NaO4 tetrahedra and edges with six FeO6 octahedra. There is two shorter (1.92 Å) and four longer (1.97 Å) Fe–O bond length. There are three inequivalent O sites. In the first O site, O is bonded to one Na and three Fe atoms to form a mixture of edge and corner-sharing ONaFe3 tetrahedra. In the second O site, O is bonded to one Na and three Fe atoms to form a mixture of distorted edge and corner-sharing ONaFe3 tetrahedra. In the third O site, O is bonded to one Na and three Fe atoms to form a mixture of edge and corner-sharing ONaFe3 tetrahedra.