Na2FeO3 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(3) and three equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with five equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, and edges with three equivalent Na(1)O5 trigonal bipyramids. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. Fe(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra and corners with five equivalent Na(1)O5 trigonal bipyramids. There are three inequivalent O sites. In the first O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Na(1), three equivalent Na(2), and one Fe(1) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(2) and two equivalent Fe(1) atoms. In the third O site, O(2) is bonded to two equivalent Na(2), three equivalent Na(1), and one Fe(1) atom to form a mixture of distorted edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles are 19°.
Na2FeO3 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(3) and three equivalent O(2) atoms to form distorted NaO5 trigonal bipyramids that share corners with five equivalent Fe(1)O4 tetrahedra, corners with two equivalent Na(1)O5 trigonal bipyramids, and edges with three equivalent Na(1)O5 trigonal bipyramids. There is one shorter (2.36 Å) and one longer (2.43 Å) Na(1)-O(3) bond length. There is one shorter (2.44 Å) and two longer (2.82 Å) Na(1)-O(2) bond lengths. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. Both Na(2)-O(1) bond lengths are 2.46 Å. There is one shorter (2.32 Å) and one longer (2.56 Å) Na(2)-O(2) bond length. There is one shorter (2.73 Å) and two longer (2.85 Å) Na(2)-O(3) bond lengths. Fe(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form FeO4 tetrahedra that share corners with two equivalent Fe(1)O4 tetrahedra and corners with five equivalent Na(1)O5 trigonal bipyramids. The Fe(1)-O(2) bond length is 1.79 Å. The Fe(1)-O(3) bond length is 1.77 Å. Both Fe(1)-O(1) bond lengths are 1.86 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Na(1), three equivalent Na(2), and one Fe(1) atom. In the second O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(2) and two equivalent Fe(1) atoms. In the third O site, O(2) is bonded to two equivalent Na(2), three equivalent Na(1), and one Fe(1) atom to form a mixture of distorted edge and corner-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles are 19°.