Na(Fe2O3)4 is Spinel-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Fe(4)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. In the second Na site, Na(2) is bonded to two equivalent O(8) and four equivalent O(9) atoms to form NaO6 octahedra that share corners with six equivalent Fe(5)O4 tetrahedra, edges with two equivalent Fe(7)O6 octahedra, and edges with four equivalent Fe(6)O6 octahedra. There are seven inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent Fe(2)O4 tetrahedra, corners with three equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Fe(7)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(6)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form FeO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Fe(7)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with four equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-60°. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Fe(4)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(3), one O(7), and two equivalent O(1) atoms to form FeO4 tetrahedra that share  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Fe(6)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. In the fifth Fe site, Fe(5) is bonded to one O(6), one O(8), and two equivalent O(9) atoms to form FeO4 tetrahedra that share corners with three equivalent Na(2)O6 octahedra, corners with three equivalent Fe(7)O6 octahedra, and corners with six equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-61°. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with three equivalent Fe(5)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(6)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. In the seventh Fe site, Fe(7) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(9) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with three equivalent Fe(5)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with four equivalent Fe(6)O6 octahedra. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(2), and two equivalent Fe(6) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(4), and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Na(1), one Fe(2), and two equivalent Fe(3) atoms. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(2), one Fe(6), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Fe(5), one Fe(7), and two equivalent Fe(6) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Fe(4), one Fe(7), and two equivalent Fe(6) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Na(2), one Fe(5), and two equivalent Fe(6) atoms. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Na(2), one Fe(5), one Fe(6), and one Fe(7) atom.
Na(Fe2O3)4 is Spinel-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form NaO6 octahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Fe(4)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with four equivalent Fe(3)O6 octahedra. Both Na(1)-O(4) bond lengths are 2.21 Å. All Na(1)-O(1) bond lengths are 2.25 Å. In the second Na site, Na(2) is bonded to two equivalent O(8) and four equivalent O(9) atoms to form NaO6 octahedra that share corners with six equivalent Fe(5)O4 tetrahedra, edges with two equivalent Fe(7)O6 octahedra, and edges with four equivalent Fe(6)O6 octahedra. Both Na(2)-O(8) bond lengths are 2.25 Å. All Na(2)-O(9) bond lengths are 2.24 Å. There are seven inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with three equivalent Fe(2)O4 tetrahedra, corners with three equivalent Fe(4)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Fe(7)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(6)O6 octahedra. The Fe(1)-O(2) bond length is 2.18 Å. The Fe(1)-O(3) bond length is 2.16 Å. Both Fe(1)-O(1) bond lengths are 2.03 Å. Both Fe(1)-O(5) bond lengths are 2.09 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form FeO4 tetrahedra that share  a cornercorner with one Na(1)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Fe(7)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with four equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-60°. The Fe(2)-O(2) bond length is 1.98 Å. The Fe(2)-O(4) bond length is 1.88 Å. Both Fe(2)-O(5) bond lengths are 1.98 Å. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Fe(2)O4 tetrahedra, corners with four equivalent Fe(4)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. Both Fe(3)-O(1) bond lengths are 2.04 Å. Both Fe(3)-O(3) bond lengths are 2.08 Å. Both Fe(3)-O(4) bond lengths are 2.07 Å. In the fourth Fe site, Fe(4) is bonded to one O(3), one O(7), and two equivalent O(1) atoms to form FeO4 tetrahedra that share  a cornercorner with one Fe(7)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Fe(6)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra, and corners with four equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-63°. The Fe(4)-O(3) bond length is 1.96 Å. The Fe(4)-O(7) bond length is 2.04 Å. Both Fe(4)-O(1) bond lengths are 1.88 Å. In the fifth Fe site, Fe(5) is bonded to one O(6), one O(8), and two equivalent O(9) atoms to form FeO4 tetrahedra that share corners with three equivalent Na(2)O6 octahedra, corners with three equivalent Fe(7)O6 octahedra, and corners with six equivalent Fe(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-61°. The Fe(5)-O(6) bond length is 2.03 Å. The Fe(5)-O(8) bond length is 1.91 Å. Both Fe(5)-O(9) bond lengths are 1.91 Å. In the sixth Fe site, Fe(6) is bonded to one O(2), one O(5), one O(6), one O(7), one O(8), and one O(9) atom to form FeO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with three equivalent Fe(5)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Fe(6)O6 octahedra, and edges with two equivalent Fe(7)O6 octahedra. The Fe(6)-O(2) bond length is 2.05 Å. The Fe(6)-O(5) bond length is 2.07 Å. The Fe(6)-O(6) bond length is 2.11 Å. The Fe(6)-O(7) bond length is 2.06 Å. The Fe(6)-O(8) bond length is 2.05 Å. The Fe(6)-O(9) bond length is 2.05 Å. In the seventh Fe site, Fe(7) is bonded to one O(6), one O(7), two equivalent O(5), and two equivalent O(9) atoms to form FeO6 octahedra that share  a cornercorner with one Fe(4)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with three equivalent Fe(5)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra, and edges with four equivalent Fe(6)O6 octahedra. The Fe(7)-O(6) bond length is 2.11 Å. The Fe(7)-O(7) bond length is 2.08 Å. Both Fe(7)-O(5) bond lengths are 2.05 Å. Both Fe(7)-O(9) bond lengths are 2.04 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(1), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(2), and two equivalent Fe(6) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(4), and two equivalent Fe(3) atoms. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Na(1), one Fe(2), and two equivalent Fe(3) atoms. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Fe(1), one Fe(2), one Fe(6), and one Fe(7) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to one Fe(5), one Fe(7), and two equivalent Fe(6) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Fe(4), one Fe(7), and two equivalent Fe(6) atoms. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Na(2), one Fe(5), and two equivalent Fe(6) atoms. In the ninth O site, O(9) is bonded in a rectangular see-saw-like geometry to one Na(2), one Fe(5), one Fe(6), and one Fe(7) atom.