Na4SeO5 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(3), one O(8), two equivalent O(6), and two equivalent O(9) atoms 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(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Se(1)O5 trigonal bipyramids,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with three equivalent Na(7)O6 octahedra,  an edgeedge with one Se(2)O5 square pyramid, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 11-33°. In the second Na site, Na(2) is bonded to one O(4), one O(5), two equivalent O(1), 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(4)O6 octahedra,  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra,  a cornercorner with one Se(2)O5 square pyramid,  a cornercorner with one Se(1)O5 trigonal bipyramid,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with three equivalent Na(9)O6 octahedra, and edges with two equivalent Se(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-35°. In the third Na site, Na(3) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(4) 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 two equivalent Se(2)O5 square pyramids, edges with two equivalent Na(7)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with two equivalent Na(9)O6 octahedra, edges with four equivalent Na(5)O6 octahedra, and edges with two equivalent Se(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 11-21°. In the fourth Na site, Na(4) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(8) atoms to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Se(2)O5 square pyramids, corners with two equivalent Se(1)O5 trigonal bipyramids, edges with two equivalent Na(7)O6 octahedra, edges with two equivalent Na(9)O6 octahedra, and edges with four equivalent Na(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-35°. In the fifth Na site, Na(5) is bonded to one O(3), one O(4), one O(7), one O(9), and two equivalent O(10) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with two equivalent Na(9)O6 octahedra,  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(7)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with two equivalent Se(2)O5 square pyramids, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-26°. In the sixth Na site, Na(6) is bonded to one O(1), one O(5), one O(6), one O(8), and two equivalent O(2) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with two equivalent Na(9)O6 octahedra,  a cornercorner with one Se(2)O5 square pyramid,  a cornercorner with one Se(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(6)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(4)O6 octahedra,  an edgeedge with one Se(2)O5 square pyramid, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 24-34°. In the seventh Na site, Na(7) is bonded to one O(10), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Na(5)O6 octahedra, corners with two equivalent Na(6)O6 octahedra, corners with two equivalent Se(1)O5 trigonal bipyramids,  an edgeedge with one Na(3)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(8)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with two equivalent Se(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 10-33°. In the eighth Na site, Na(8) is bonded to one O(1), one O(3), one O(4), one O(6), one O(7), and one O(9) atom 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(7)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Se(2)O5 square pyramids,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(5)O6 octahedra, and edges with two equivalent Se(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-27°. In the ninth Na site, Na(9) is bonded to one O(1), one O(10), one O(2), one O(4), one O(5), and one O(7) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Na(5)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  a cornercorner with one Se(2)O5 square pyramid,  a cornercorner with one Se(1)O5 trigonal bipyramid,  an edgeedge with one Na(3)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(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with three equivalent Na(2)O6 octahedra,  an edgeedge with one Se(2)O5 square pyramid, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 20-34°. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(5), one O(6), one O(7), and one O(9) atom to form SeO5 trigonal bipyramids that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(4)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(7)O6 octahedra,  an edgeedge with one Na(1)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 two equivalent Na(2)O6 octahedra, and edges with two equivalent Na(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-73°. In the second Se site, Se(2) is bonded to one O(10), one O(2), one O(3), one O(4), and one O(8) atom to form SeO5 square pyramids that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)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(6)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(5)O6 octahedra, and edges with two equivalent Na(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-72°. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(6), one Na(8), one Na(9), two equivalent Na(2), and one Se(1) atom to form distorted ONa5Se octahedra that share  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(6)Na5Se octahedra,  a cornercorner with one O(7)Na5Se octahedra,  a cornercorner with one O(5)Na4Se trigonal bipyramid,  a cornercorner with one O(8)Na4Se trigonal bipyramid,  an edgeedge with one O(1)Na5Se octahedra,  an edgeedge with one O(6)Na5Se octahedra, edges with two equivalent O(4)Na5Se octahedra, edges with three equivalent O(7)Na5Se octahedra, and edges with two equivalent O(5)Na4Se trigonal bipyramids. The corner-sharing octahedral tilt angles range from 12-18°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(4), one Na(7), one Na(9), two equivalent Na(6), and one Se(2) atom. In the third O site, O(3) is bonded to one Na(1), one Na(3), one Na(5), one Na(7), one Na(8), and one Se(2) atom to form ONa5Se octahedra that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra,  a cornercorner with one O(8)Na4Se trigonal bipyramid,  an edgeedge with one O(7)Na5Se octahedra, edges with two equivalent O(4)Na5Se octahedra, edges with two equivalent O(6)Na5Se octahedra, and  an edgeedge with one O(8)Na4Se trigonal bipyramid. The corner-sharing octahedral tilt angles range from 0-13°. In the fourth O site, O(4) is bonded to one Na(2), one Na(3), one Na(5), one Na(8), one Na(9), and one Se(2) atom to form distorted ONa5Se octahedra that share  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra,  a cornercorner with one O(6)Na5Se octahedra,  a cornercorner with one O(7)Na5Se octahedra,  a cornercorner with one O(8)Na4Se trigonal bipyramid, corners with two equivalent O(5)Na4Se trigonal bipyramids, edges with two equivalent O(1)Na5Se octahedra, edges with two equivalent O(3)Na5Se octahedra, and edges with two equivalent O(7)Na5Se octahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the fifth O site, O(5) is bonded to one Na(2), one Na(4), one Na(6), one Na(9), and one Se(1) atom to form distorted ONa4Se trigonal bipyramids that share  a cornercorner with one O(1)Na5Se octahedra, corners with two equivalent O(4)Na5Se octahedra,  a cornercorner with one O(5)Na4Se trigonal bipyramid, corners with three equivalent O(8)Na4Se trigonal bipyramids,  an edgeedge with one O(6)Na5Se octahedra, edges with two equivalent O(1)Na5Se octahedra, and edges with two equivalent O(7)Na5Se octahedra. The corner-sharing octahedral tilt angles range from 21-81°. In the sixth O site, O(6) is bonded to one Na(6), one Na(7), one Na(8), two equivalent Na(1), and one Se(1) atom to form distorted ONa5Se octahedra that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra, corners with two equivalent O(8)Na4Se trigonal bipyramids,  an edgeedge with one O(1)Na5Se octahedra,  an edgeedge with one O(6)Na5Se octahedra,  an edgeedge with one O(7)Na5Se octahedra, edges with two equivalent O(3)Na5Se octahedra,  an edgeedge with one O(5)Na4Se trigonal bipyramid, and  an edgeedge with one O(8)Na4Se trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-18°. In the seventh O site, O(7) is bonded to one Na(5), one Na(8), one Na(9), two equivalent Na(2), and one Se(1) atom to form ONa5Se octahedra that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra,  an edgeedge with one O(3)Na5Se octahedra,  an edgeedge with one O(6)Na5Se octahedra,  an edgeedge with one O(7)Na5Se octahedra, edges with two equivalent O(4)Na5Se octahedra, edges with three equivalent O(1)Na5Se octahedra, and edges with two equivalent O(5)Na4Se trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. In the eighth O site, O(8) is bonded to one Na(1), one Na(4), one Na(6), one Na(7), and one Se(2) atom to form distorted ONa4Se trigonal bipyramids that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra, corners with two equivalent O(6)Na5Se octahedra,  a cornercorner with one O(8)Na4Se trigonal bipyramid, corners with three equivalent O(5)Na4Se trigonal bipyramids,  an edgeedge with one O(3)Na5Se octahedra, and  an edgeedge with one O(6)Na5Se octahedra. The corner-sharing octahedral tilt angles range from 19-85°. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Na(5), one Na(7), one Na(8), two equivalent Na(1), and one Se(1) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Na(3), one Na(7), one Na(9), two equivalent Na(5), and one Se(2) atom.
Na4SeO5 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(3), one O(8), two equivalent O(6), and two equivalent O(9) atoms 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(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Se(1)O5 trigonal bipyramids,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with three equivalent Na(7)O6 octahedra,  an edgeedge with one Se(2)O5 square pyramid, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 11-33°. The Na(1)-O(3) bond length is 2.42 Å. The Na(1)-O(8) bond length is 2.35 Å. There is one shorter (2.31 Å) and one longer (2.68 Å) Na(1)-O(6) bond length. There is one shorter (2.33 Å) and one longer (2.37 Å) Na(1)-O(9) bond length. In the second Na site, Na(2) is bonded to one O(4), one O(5), two equivalent O(1), 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(4)O6 octahedra,  a cornercorner with one Na(5)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(8)O6 octahedra,  a cornercorner with one Se(2)O5 square pyramid,  a cornercorner with one Se(1)O5 trigonal bipyramid,  an edgeedge with one Na(5)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with three equivalent Na(9)O6 octahedra, and edges with two equivalent Se(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-35°. The Na(2)-O(4) bond length is 2.36 Å. The Na(2)-O(5) bond length is 2.40 Å. There is one shorter (2.36 Å) and one longer (2.64 Å) Na(2)-O(1) bond length. There is one shorter (2.38 Å) and one longer (2.40 Å) Na(2)-O(7) bond length. In the third Na site, Na(3) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(4) 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 two equivalent Se(2)O5 square pyramids, edges with two equivalent Na(7)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with two equivalent Na(9)O6 octahedra, edges with four equivalent Na(5)O6 octahedra, and edges with two equivalent Se(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 11-21°. Both Na(3)-O(10) bond lengths are 2.83 Å. Both Na(3)-O(3) bond lengths are 2.27 Å. Both Na(3)-O(4) bond lengths are 2.28 Å. In the fourth Na site, Na(4) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(8) atoms to form NaO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Se(2)O5 square pyramids, corners with two equivalent Se(1)O5 trigonal bipyramids, edges with two equivalent Na(7)O6 octahedra, edges with two equivalent Na(9)O6 octahedra, and edges with four equivalent Na(6)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-35°. Both Na(4)-O(2) bond lengths are 2.69 Å. Both Na(4)-O(5) bond lengths are 2.34 Å. Both Na(4)-O(8) bond lengths are 2.40 Å. In the fifth Na site, Na(5) is bonded to one O(3), one O(4), one O(7), one O(9), and two equivalent O(10) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with two equivalent Na(9)O6 octahedra,  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(7)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(3)O6 octahedra, edges with two equivalent Na(8)O6 octahedra, edges with two equivalent Se(2)O5 square pyramids, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 10-26°. The Na(5)-O(3) bond length is 2.38 Å. The Na(5)-O(4) bond length is 2.32 Å. The Na(5)-O(7) bond length is 2.33 Å. The Na(5)-O(9) bond length is 2.38 Å. There is one shorter (2.29 Å) and one longer (2.36 Å) Na(5)-O(10) bond length. In the sixth Na site, Na(6) is bonded to one O(1), one O(5), one O(6), one O(8), and two equivalent O(2) atoms to form distorted NaO6 octahedra that share  a cornercorner with one Na(1)O6 octahedra,  a cornercorner with one Na(2)O6 octahedra, corners with two equivalent Na(7)O6 octahedra, corners with two equivalent Na(9)O6 octahedra,  a cornercorner with one Se(2)O5 square pyramid,  a cornercorner with one Se(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(6)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(4)O6 octahedra,  an edgeedge with one Se(2)O5 square pyramid, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 24-34°. The Na(6)-O(1) bond length is 2.48 Å. The Na(6)-O(5) bond length is 2.31 Å. The Na(6)-O(6) bond length is 2.45 Å. The Na(6)-O(8) bond length is 2.27 Å. There is one shorter (2.35 Å) and one longer (2.44 Å) Na(6)-O(2) bond length. In the seventh Na site, Na(7) is bonded to one O(10), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Na(5)O6 octahedra, corners with two equivalent Na(6)O6 octahedra, corners with two equivalent Se(1)O5 trigonal bipyramids,  an edgeedge with one Na(3)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(8)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with two equivalent Se(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 10-33°. The Na(7)-O(10) bond length is 2.41 Å. The Na(7)-O(2) bond length is 2.38 Å. The Na(7)-O(3) bond length is 2.34 Å. The Na(7)-O(6) bond length is 2.35 Å. The Na(7)-O(8) bond length is 2.24 Å. The Na(7)-O(9) bond length is 2.81 Å. In the eighth Na site, Na(8) is bonded to one O(1), one O(3), one O(4), one O(6), one O(7), and one O(9) atom 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(7)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Se(2)O5 square pyramids,  an edgeedge with one Na(3)O6 octahedra,  an edgeedge with one Na(6)O6 octahedra,  an edgeedge with one Na(7)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Na(5)O6 octahedra, and edges with two equivalent Se(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 15-27°. The Na(8)-O(1) bond length is 2.33 Å. The Na(8)-O(3) bond length is 2.47 Å. The Na(8)-O(4) bond length is 2.74 Å. The Na(8)-O(6) bond length is 2.38 Å. The Na(8)-O(7) bond length is 2.27 Å. The Na(8)-O(9) bond length is 2.25 Å. In the ninth Na site, Na(9) is bonded to one O(1), one O(10), one O(2), one O(4), one O(5), and one O(7) atom to form distorted NaO6 octahedra that share  a cornercorner with one Na(8)O6 octahedra, corners with two equivalent Na(5)O6 octahedra, corners with two equivalent Na(6)O6 octahedra,  a cornercorner with one Se(2)O5 square pyramid,  a cornercorner with one Se(1)O5 trigonal bipyramid,  an edgeedge with one Na(3)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(7)O6 octahedra,  an edgeedge with one Na(8)O6 octahedra, edges with three equivalent Na(2)O6 octahedra,  an edgeedge with one Se(2)O5 square pyramid, and  an edgeedge with one Se(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 20-34°. The Na(9)-O(1) bond length is 2.41 Å. The Na(9)-O(10) bond length is 2.38 Å. The Na(9)-O(2) bond length is 2.33 Å. The Na(9)-O(4) bond length is 2.35 Å. The Na(9)-O(5) bond length is 2.28 Å. The Na(9)-O(7) bond length is 2.52 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to one O(1), one O(5), one O(6), one O(7), and one O(9) atom to form SeO5 trigonal bipyramids that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(4)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)O6 octahedra, corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(7)O6 octahedra,  an edgeedge with one Na(1)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 two equivalent Na(2)O6 octahedra, and edges with two equivalent Na(8)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-73°. The Se(1)-O(1) bond length is 1.79 Å. The Se(1)-O(5) bond length is 1.76 Å. The Se(1)-O(6) bond length is 1.80 Å. The Se(1)-O(7) bond length is 1.72 Å. The Se(1)-O(9) bond length is 1.78 Å. In the second Se site, Se(2) is bonded to one O(10), one O(2), one O(3), one O(4), and one O(8) atom to form SeO5 square pyramids that share  a cornercorner with one Na(2)O6 octahedra,  a cornercorner with one Na(3)O6 octahedra,  a cornercorner with one Na(6)O6 octahedra,  a cornercorner with one Na(9)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(6)O6 octahedra,  an edgeedge with one Na(9)O6 octahedra, edges with two equivalent Na(5)O6 octahedra, and edges with two equivalent Na(7)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-72°. The Se(2)-O(10) bond length is 1.78 Å. The Se(2)-O(2) bond length is 1.76 Å. The Se(2)-O(3) bond length is 1.73 Å. The Se(2)-O(4) bond length is 1.81 Å. The Se(2)-O(8) bond length is 1.76 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded to one Na(6), one Na(8), one Na(9), two equivalent Na(2), and one Se(1) atom to form distorted ONa5Se octahedra that share  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(6)Na5Se octahedra,  a cornercorner with one O(7)Na5Se octahedra,  a cornercorner with one O(5)Na4Se trigonal bipyramid,  a cornercorner with one O(8)Na4Se trigonal bipyramid,  an edgeedge with one O(1)Na5Se octahedra,  an edgeedge with one O(6)Na5Se octahedra, edges with two equivalent O(4)Na5Se octahedra, edges with three equivalent O(7)Na5Se octahedra, and edges with two equivalent O(5)Na4Se trigonal bipyramids. The corner-sharing octahedral tilt angles range from 12-18°. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(4), one Na(7), one Na(9), two equivalent Na(6), and one Se(2) atom. In the third O site, O(3) is bonded to one Na(1), one Na(3), one Na(5), one Na(7), one Na(8), and one Se(2) atom to form ONa5Se octahedra that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra,  a cornercorner with one O(8)Na4Se trigonal bipyramid,  an edgeedge with one O(7)Na5Se octahedra, edges with two equivalent O(4)Na5Se octahedra, edges with two equivalent O(6)Na5Se octahedra, and  an edgeedge with one O(8)Na4Se trigonal bipyramid. The corner-sharing octahedral tilt angles range from 0-13°. In the fourth O site, O(4) is bonded to one Na(2), one Na(3), one Na(5), one Na(8), one Na(9), and one Se(2) atom to form distorted ONa5Se octahedra that share  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra,  a cornercorner with one O(6)Na5Se octahedra,  a cornercorner with one O(7)Na5Se octahedra,  a cornercorner with one O(8)Na4Se trigonal bipyramid, corners with two equivalent O(5)Na4Se trigonal bipyramids, edges with two equivalent O(1)Na5Se octahedra, edges with two equivalent O(3)Na5Se octahedra, and edges with two equivalent O(7)Na5Se octahedra. The corner-sharing octahedral tilt angles range from 0-15°. In the fifth O site, O(5) is bonded to one Na(2), one Na(4), one Na(6), one Na(9), and one Se(1) atom to form distorted ONa4Se trigonal bipyramids that share  a cornercorner with one O(1)Na5Se octahedra, corners with two equivalent O(4)Na5Se octahedra,  a cornercorner with one O(5)Na4Se trigonal bipyramid, corners with three equivalent O(8)Na4Se trigonal bipyramids,  an edgeedge with one O(6)Na5Se octahedra, edges with two equivalent O(1)Na5Se octahedra, and edges with two equivalent O(7)Na5Se octahedra. The corner-sharing octahedral tilt angles range from 21-81°. In the sixth O site, O(6) is bonded to one Na(6), one Na(7), one Na(8), two equivalent Na(1), and one Se(1) atom to form distorted ONa5Se octahedra that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra, corners with two equivalent O(8)Na4Se trigonal bipyramids,  an edgeedge with one O(1)Na5Se octahedra,  an edgeedge with one O(6)Na5Se octahedra,  an edgeedge with one O(7)Na5Se octahedra, edges with two equivalent O(3)Na5Se octahedra,  an edgeedge with one O(5)Na4Se trigonal bipyramid, and  an edgeedge with one O(8)Na4Se trigonal bipyramid. The corner-sharing octahedral tilt angles range from 15-18°. In the seventh O site, O(7) is bonded to one Na(5), one Na(8), one Na(9), two equivalent Na(2), and one Se(1) atom to form ONa5Se octahedra that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra,  an edgeedge with one O(3)Na5Se octahedra,  an edgeedge with one O(6)Na5Se octahedra,  an edgeedge with one O(7)Na5Se octahedra, edges with two equivalent O(4)Na5Se octahedra, edges with three equivalent O(1)Na5Se octahedra, and edges with two equivalent O(5)Na4Se trigonal bipyramids. The corner-sharing octahedral tilt angles are 13°. In the eighth O site, O(8) is bonded to one Na(1), one Na(4), one Na(6), one Na(7), and one Se(2) atom to form distorted ONa4Se trigonal bipyramids that share  a cornercorner with one O(1)Na5Se octahedra,  a cornercorner with one O(3)Na5Se octahedra,  a cornercorner with one O(4)Na5Se octahedra, corners with two equivalent O(6)Na5Se octahedra,  a cornercorner with one O(8)Na4Se trigonal bipyramid, corners with three equivalent O(5)Na4Se trigonal bipyramids,  an edgeedge with one O(3)Na5Se octahedra, and  an edgeedge with one O(6)Na5Se octahedra. The corner-sharing octahedral tilt angles range from 19-85°. In the ninth O site, O(9) is bonded in a 6-coordinate geometry to one Na(5), one Na(7), one Na(8), two equivalent Na(1), and one Se(1) atom. In the tenth O site, O(10) is bonded in a 6-coordinate geometry to one Na(3), one Na(7), one Na(9), two equivalent Na(5), and one Se(2) atom.