Materials Data on Na4FeO4 by Materials Project
Na4FeO4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Na sites. In the first Na site, Na is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Na–O bond distances ranging from 2.36–2.88 Å. In the second Na site, Na is bonded in a distorted see-saw-like geometry to four O atoms. There are a spread of Na–O bond distances ranging from 2.31–2.37 Å. In the third Na site, Na is bonded to five O atoms to form distorted NaO5 trigonal bipyramids that share corners with three equivalent FeO4 tetrahedra, an edgeedge with one FeO4 tetrahedra, and edges with two equivalent NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.34–2.44 Å. In the fourth Na site, Na is bonded in a 4-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.36–2.88 Å. Fe is bonded to four O atoms to form FeO4 tetrahedra that share corners with three equivalent NaO5 trigonal bipyramids and an edgeedge with one NaO5 trigonal bipyramid. All Fe–O bond lengths are 1.83 Å. There are four inequivalent O sites. In the first O site, O is bonded in a 6-coordinate geometry to five Na and one Fe atom. In the second O site, O is bonded to five Na and one Fe atom to form a mixture of edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedra tilt angles range from 18–21°. In the third O site, O is bonded to five Na and one Fe atom to form a mixture of edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedra tilt angles range from 18–21°. In the fourth O site, O is bonded in a 6-coordinate geometry to five Na and one Fe atom.