Na2FeO3 crystallizes in the monoclinic Cc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Na(1)O6 octahedra, edges with five equivalent Na(2)O6 octahedra, and edges with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-31°. In the second Na site, Na(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Na(2)O6 octahedra, edges with five equivalent Na(1)O6 octahedra, and edges with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-35°. Fe(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form FeO5 trigonal bipyramids that share corners with four equivalent Na(1)O6 octahedra, corners with four equivalent Na(2)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 6-86°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Fe(1) atoms to form ONa4Fe2 octahedra that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with two equivalent O(3)Na4Fe2 octahedra, corners with two equivalent O(2)Na4Fe trigonal bipyramids, edges with two equivalent O(1)Na4Fe2 octahedra, edges with five equivalent O(3)Na4Fe2 octahedra, and edges with four equivalent O(2)Na4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-14°. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and one Fe(1) atom to form distorted ONa4Fe trigonal bipyramids that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with four equivalent O(3)Na4Fe2 octahedra, corners with four equivalent O(2)Na4Fe trigonal bipyramids, edges with three equivalent O(3)Na4Fe2 octahedra, and edges with four equivalent O(1)Na4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 9-82°. In the third O site, O(3) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Fe(1) atoms to form distorted ONa4Fe2 octahedra that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with two equivalent O(3)Na4Fe2 octahedra, corners with four equivalent O(2)Na4Fe trigonal bipyramids, edges with two equivalent O(3)Na4Fe2 octahedra, edges with five equivalent O(1)Na4Fe2 octahedra, and edges with three equivalent O(2)Na4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-14°.
Na2FeO3 crystallizes in the monoclinic Cc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Na(1)O6 octahedra, edges with five equivalent Na(2)O6 octahedra, and edges with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-31°. There is one shorter (2.34 Å) and one longer (2.41 Å) Na(1)-O(1) bond length. There is one shorter (2.28 Å) and one longer (2.40 Å) Na(1)-O(2) bond length. There is one shorter (2.31 Å) and one longer (2.42 Å) Na(1)-O(3) bond length. In the second Na site, Na(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Na(2)O6 octahedra, edges with five equivalent Na(1)O6 octahedra, and edges with three equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-35°. There is one shorter (2.37 Å) and one longer (2.41 Å) Na(2)-O(1) bond length. There is one shorter (2.22 Å) and one longer (2.25 Å) Na(2)-O(2) bond length. There is one shorter (2.51 Å) and one longer (2.63 Å) Na(2)-O(3) bond length. Fe(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(3) atoms to form FeO5 trigonal bipyramids that share corners with four equivalent Na(1)O6 octahedra, corners with four equivalent Na(2)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, edges with three equivalent Na(2)O6 octahedra, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 6-86°. The Fe(1)-O(2) bond length is 1.74 Å. There is one shorter (1.85 Å) and one longer (2.01 Å) Fe(1)-O(1) bond length. There is one shorter (1.90 Å) and one longer (1.93 Å) Fe(1)-O(3) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Fe(1) atoms to form ONa4Fe2 octahedra that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with two equivalent O(3)Na4Fe2 octahedra, corners with two equivalent O(2)Na4Fe trigonal bipyramids, edges with two equivalent O(1)Na4Fe2 octahedra, edges with five equivalent O(3)Na4Fe2 octahedra, and edges with four equivalent O(2)Na4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-14°. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Na(2), and one Fe(1) atom to form distorted ONa4Fe trigonal bipyramids that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with four equivalent O(3)Na4Fe2 octahedra, corners with four equivalent O(2)Na4Fe trigonal bipyramids, edges with three equivalent O(3)Na4Fe2 octahedra, and edges with four equivalent O(1)Na4Fe2 octahedra. The corner-sharing octahedral tilt angles range from 9-82°. In the third O site, O(3) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Fe(1) atoms to form distorted ONa4Fe2 octahedra that share corners with two equivalent O(1)Na4Fe2 octahedra, corners with two equivalent O(3)Na4Fe2 octahedra, corners with four equivalent O(2)Na4Fe trigonal bipyramids, edges with two equivalent O(3)Na4Fe2 octahedra, edges with five equivalent O(1)Na4Fe2 octahedra, and edges with three equivalent O(2)Na4Fe trigonal bipyramids. The corner-sharing octahedral tilt angles range from 4-14°.