Na4FeO5 crystallizes in the triclinic P-1 space group. There are nine inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), one O(3), one O(8), and two equivalent O(7) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, corners with two equivalent Na(8)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(5)O6 octahedra, edges with two equivalent Fe(2)O5 square pyramids, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-24°. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(4)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Fe(2)O5 square pyramids,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Na(7)O6 octahedra, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-22°. In the third Na site, Na(3) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with three equivalent Na(4)O6 octahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 9-36°. In the fourth Na site, Na(4) is bonded to one O(1), one O(10), one O(2), one O(4), one O(6), and one O(7) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(6)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with three equivalent Na(3)O6 octahedra, and edges with two equivalent Fe(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 10-38°. In the fifth Na site, Na(5) is bonded to two equivalent O(2), two equivalent O(7), and two equivalent O(8) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with two equivalent Fe(2)O5 square pyramids, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with two equivalent Fe(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 9-18°. In the sixth Na site, Na(6) is bonded to one O(4), one O(5), one O(6), one O(9), and two equivalent O(10) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, corners with two equivalent Na(8)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(9)O6 octahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 22-41°. In the seventh Na site, Na(7) is bonded to one O(8), one O(9), two equivalent O(3), and two equivalent O(5) atoms to form NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(7)O6 octahedra, edges with three equivalent Na(8)O6 octahedra, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-37°. In the eighth Na site, Na(8) is bonded to one O(10), one O(3), one O(5), one O(7), one O(8), and one O(9) atom to form NaO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with three equivalent Na(7)O6 octahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-41°. In the ninth Na site, Na(9) is bonded to two equivalent O(10), two equivalent O(6), and two equivalent O(9) atoms to form NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with four equivalent Fe(2)O5 square pyramids, corners with two equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, and edges with four equivalent Na(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-37°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(9) atom to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Na(4)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and edges with two equivalent Na(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-73°. In the second Fe site, Fe(2) is bonded to one O(10), one O(2), one O(6), one O(7), and one O(8) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(9)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, and edges with two equivalent Na(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-73°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(4), two equivalent Na(3), and one Fe(1) atom to form distorted ONa5Fe octahedra that share  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(3)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra,  an edgeedge with one O(3)Na5Fe octahedra,  an edgeedge with one O(5)Na5Fe octahedra,  an edgeedge with one O(8)Na5Fe octahedra, edges with two equivalent O(2)Na5Fe octahedra, and  an edgeedge with one O(6)Na4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles range from 9-14°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), and one Fe(2) atom to form ONa5Fe octahedra that share  a cornercorner with one O(1)Na5Fe octahedra,  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(5)Na5Fe octahedra,  a cornercorner with one O(8)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(3)Na5Fe octahedra, edges with two equivalent O(1)Na5Fe octahedra, edges with two equivalent O(8)Na5Fe octahedra, and  an edgeedge with one O(6)Na4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(8), two equivalent Na(7), and one Fe(1) atom to form a mixture of distorted corner and edge-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles range from 12-14°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(2), one Na(4), one Na(6), two equivalent Na(3), and one Fe(1) atom. In the fifth O site, O(5) is bonded to one Na(2), one Na(6), one Na(8), two equivalent Na(7), and one Fe(1) atom to form distorted ONa5Fe octahedra that share  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(3)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra,  an edgeedge with one O(5)Na5Fe octahedra, edges with two equivalent O(8)Na5Fe octahedra, and edges with three equivalent O(3)Na5Fe octahedra. The corner-sharing octahedral tilt angles range from 11-12°. In the sixth O site, O(6) is bonded to one Na(3), one Na(4), one Na(6), one Na(9), and one Fe(2) atom to form distorted ONa4Fe trigonal bipyramids that share  a cornercorner with one O(1)Na5Fe octahedra,  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(5)Na5Fe octahedra,  a cornercorner with one O(8)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra, and  an edgeedge with one O(2)Na5Fe octahedra. The corner-sharing octahedral tilt angles range from 20-79°. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Na(4), one Na(5), one Na(8), two equivalent Na(1), and one Fe(2) atom. In the eighth O site, O(8) is bonded to one Na(1), one Na(2), one Na(5), one Na(7), one Na(8), and one Fe(2) atom to form distorted ONa5Fe octahedra that share  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(3)Na5Fe octahedra,  a cornercorner with one O(8)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra, edges with two equivalent O(2)Na5Fe octahedra, edges with two equivalent O(3)Na5Fe octahedra, and edges with two equivalent O(5)Na5Fe octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Na(6), one Na(7), one Na(8), one Na(9), and one Fe(1) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Na(4), one Na(8), one Na(9), two equivalent Na(6), and one Fe(2) atom.
Na4FeO5 crystallizes in the triclinic P-1 space group. There are nine inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), one O(3), one O(8), and two equivalent O(7) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, corners with two equivalent Na(8)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(5)O6 octahedra, edges with two equivalent Fe(2)O5 square pyramids, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-24°. The Na(1)-O(1) bond length is 2.34 Å. The Na(1)-O(2) bond length is 2.36 Å. The Na(1)-O(3) bond length is 2.29 Å. The Na(1)-O(8) bond length is 2.33 Å. There is one shorter (2.30 Å) and one longer (2.31 Å) Na(1)-O(7) bond length. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(8) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(4)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Fe(2)O5 square pyramids,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Na(7)O6 octahedra, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-22°. The Na(2)-O(1) bond length is 2.26 Å. The Na(2)-O(2) bond length is 2.44 Å. The Na(2)-O(3) bond length is 2.27 Å. The Na(2)-O(4) bond length is 2.44 Å. The Na(2)-O(5) bond length is 2.35 Å. The Na(2)-O(8) bond length is 2.61 Å. In the third Na site, Na(3) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with three equivalent Na(4)O6 octahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 9-36°. The Na(3)-O(2) bond length is 2.38 Å. The Na(3)-O(6) bond length is 2.38 Å. There is one shorter (2.35 Å) and one longer (2.36 Å) Na(3)-O(1) bond length. There is one shorter (2.38 Å) and one longer (2.76 Å) Na(3)-O(4) bond length. In the fourth Na site, Na(4) is bonded to one O(1), one O(10), one O(2), one O(4), one O(6), and one O(7) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(6)O6 octahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with three equivalent Na(3)O6 octahedra, and edges with two equivalent Fe(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 10-38°. The Na(4)-O(1) bond length is 2.63 Å. The Na(4)-O(10) bond length is 2.38 Å. The Na(4)-O(2) bond length is 2.36 Å. The Na(4)-O(4) bond length is 2.36 Å. The Na(4)-O(6) bond length is 2.35 Å. The Na(4)-O(7) bond length is 2.34 Å. In the fifth Na site, Na(5) is bonded to two equivalent O(2), two equivalent O(7), and two equivalent O(8) atoms to form distorted NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with two equivalent Fe(2)O5 square pyramids, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with two equivalent Fe(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 9-18°. Both Na(5)-O(2) bond lengths are 2.25 Å. Both Na(5)-O(7) bond lengths are 2.77 Å. Both Na(5)-O(8) bond lengths are 2.27 Å. In the sixth Na site, Na(6) is bonded to one O(4), one O(5), one O(6), one O(9), and two equivalent O(10) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra, corners with two equivalent Na(4)O6 octahedra, corners with two equivalent Na(8)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(9)O6 octahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 22-41°. The Na(6)-O(4) bond length is 2.47 Å. The Na(6)-O(5) bond length is 2.37 Å. The Na(6)-O(6) bond length is 2.25 Å. The Na(6)-O(9) bond length is 2.26 Å. There is one shorter (2.33 Å) and one longer (2.44 Å) Na(6)-O(10) bond length. In the seventh Na site, Na(7) is bonded to one O(8), one O(9), two equivalent O(3), and two equivalent O(5) atoms to form NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(7)O6 octahedra, edges with three equivalent Na(8)O6 octahedra, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-37°. The Na(7)-O(8) bond length is 2.39 Å. The Na(7)-O(9) bond length is 2.42 Å. There is one shorter (2.36 Å) and one longer (2.40 Å) Na(7)-O(3) bond length. There is one shorter (2.36 Å) and one longer (2.46 Å) Na(7)-O(5) bond length. In the eighth Na site, Na(8) is bonded to one O(10), one O(3), one O(5), one O(7), one O(8), and one O(9) atom to form NaO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  a cornercorner with one Fe(2)O5 square pyramid,  a cornercorner with one Fe(1)O5 trigonal bipyramid,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(2)O6 octahedra,  an edgeedge with one Na(4)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with three equivalent Na(7)O6 octahedra,  an edgeedge with one Fe(2)O5 square pyramid, and  an edgeedge with one Fe(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-41°. The Na(8)-O(10) bond length is 2.41 Å. The Na(8)-O(3) bond length is 2.47 Å. The Na(8)-O(5) bond length is 2.39 Å. The Na(8)-O(7) bond length is 2.35 Å. The Na(8)-O(8) bond length is 2.30 Å. The Na(8)-O(9) bond length is 2.31 Å. In the ninth Na site, Na(9) is bonded to two equivalent O(10), two equivalent O(6), and two equivalent O(9) atoms to form NaO6 octahedra that share corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with four equivalent Fe(2)O5 square pyramids, corners with two equivalent Fe(1)O5 trigonal bipyramids, edges with two equivalent Na(4)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, and edges with four equivalent Na(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-37°. Both Na(9)-O(10) bond lengths are 2.65 Å. Both Na(9)-O(6) bond lengths are 2.37 Å. Both Na(9)-O(9) bond lengths are 2.36 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(9) atom to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Na(3)O6 octahedra, corners with two equivalent Na(4)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and edges with two equivalent Na(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-73°. The Fe(1)-O(1) bond length is 1.78 Å. The Fe(1)-O(3) bond length is 1.73 Å. The Fe(1)-O(4) bond length is 1.86 Å. The Fe(1)-O(5) bond length is 1.78 Å. The Fe(1)-O(9) bond length is 1.81 Å. In the second Fe site, Fe(2) is bonded to one O(10), one O(2), one O(6), one O(7), and one O(8) atom to form distorted FeO5 square pyramids that share  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(7)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with two equivalent Na(9)O6 octahedra,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, and edges with two equivalent Na(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-73°. The Fe(2)-O(10) bond length is 1.83 Å. The Fe(2)-O(2) bond length is 1.74 Å. The Fe(2)-O(6) bond length is 1.81 Å. The Fe(2)-O(7) bond length is 1.77 Å. The Fe(2)-O(8) bond length is 1.79 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(4), two equivalent Na(3), and one Fe(1) atom to form distorted ONa5Fe octahedra that share  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(3)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra,  an edgeedge with one O(3)Na5Fe octahedra,  an edgeedge with one O(5)Na5Fe octahedra,  an edgeedge with one O(8)Na5Fe octahedra, edges with two equivalent O(2)Na5Fe octahedra, and  an edgeedge with one O(6)Na4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles range from 9-14°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), and one Fe(2) atom to form ONa5Fe octahedra that share  a cornercorner with one O(1)Na5Fe octahedra,  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(5)Na5Fe octahedra,  a cornercorner with one O(8)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(3)Na5Fe octahedra, edges with two equivalent O(1)Na5Fe octahedra, edges with two equivalent O(8)Na5Fe octahedra, and  an edgeedge with one O(6)Na4Fe trigonal bipyramid. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded to one Na(1), one Na(2), one Na(8), two equivalent Na(7), and one Fe(1) atom to form a mixture of distorted corner and edge-sharing ONa5Fe octahedra. The corner-sharing octahedral tilt angles range from 12-14°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(2), one Na(4), one Na(6), two equivalent Na(3), and one Fe(1) atom. In the fifth O site, O(5) is bonded to one Na(2), one Na(6), one Na(8), two equivalent Na(7), and one Fe(1) atom to form distorted ONa5Fe octahedra that share  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(3)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra,  an edgeedge with one O(5)Na5Fe octahedra, edges with two equivalent O(8)Na5Fe octahedra, and edges with three equivalent O(3)Na5Fe octahedra. The corner-sharing octahedral tilt angles range from 11-12°. In the sixth O site, O(6) is bonded to one Na(3), one Na(4), one Na(6), one Na(9), and one Fe(2) atom to form distorted ONa4Fe trigonal bipyramids that share  a cornercorner with one O(1)Na5Fe octahedra,  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(5)Na5Fe octahedra,  a cornercorner with one O(8)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra, and  an edgeedge with one O(2)Na5Fe octahedra. The corner-sharing octahedral tilt angles range from 20-79°. In the seventh O site, O(7) is bonded in a 6-coordinate geometry to one Na(4), one Na(5), one Na(8), two equivalent Na(1), and one Fe(2) atom. In the eighth O site, O(8) is bonded to one Na(1), one Na(2), one Na(5), one Na(7), one Na(8), and one Fe(2) atom to form distorted ONa5Fe octahedra that share  a cornercorner with one O(2)Na5Fe octahedra,  a cornercorner with one O(3)Na5Fe octahedra,  a cornercorner with one O(8)Na5Fe octahedra,  a cornercorner with one O(6)Na4Fe trigonal bipyramid,  an edgeedge with one O(1)Na5Fe octahedra, edges with two equivalent O(2)Na5Fe octahedra, edges with two equivalent O(3)Na5Fe octahedra, and edges with two equivalent O(5)Na5Fe octahedra. The corner-sharing octahedral tilt angles range from 0-12°. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Na(6), one Na(7), one Na(8), one Na(9), and one Fe(1) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Na(4), one Na(8), one Na(9), two equivalent Na(6), and one Fe(2) atom.