Na6NiO4 crystallizes in the triclinic P1 space group. There are twenty-four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(10), one O(11), one O(2), and one O(3) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(17)O4 tetrahedra, corners with two equivalent Na(19)O4 tetrahedra, corners with two equivalent Na(22)O4 tetrahedra, corners with two equivalent Na(24)O4 tetrahedra,  an edgeedge with one Na(12)O4 tetrahedra,  an edgeedge with one Na(13)O4 tetrahedra,  an edgeedge with one Na(16)O4 tetrahedra,  an edgeedge with one Na(9)O4 tetrahedra, and edges with two equivalent Na(5)O4 tetrahedra. In the second Na site, Na(2) is bonded to one O(1), one O(12), one O(4), and one O(9) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(18)O4 tetrahedra, corners with two equivalent Na(20)O4 tetrahedra, corners with two equivalent Na(21)O4 tetrahedra, corners with two equivalent Na(23)O4 tetrahedra,  an edgeedge with one Na(10)O4 tetrahedra,  an edgeedge with one Na(11)O4 tetrahedra,  an edgeedge with one Na(14)O4 tetrahedra,  an edgeedge with one Na(15)O4 tetrahedra, and edges with two equivalent Na(6)O4 tetrahedra. In the third Na site, Na(3) is bonded to one O(13), one O(16), one O(6), and one O(7) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(18)O4 tetrahedra, corners with two equivalent Na(19)O4 tetrahedra, corners with two equivalent Na(22)O4 tetrahedra, corners with two equivalent Na(23)O4 tetrahedra,  an edgeedge with one Na(10)O4 tetrahedra,  an edgeedge with one Na(12)O4 tetrahedra,  an edgeedge with one Na(13)O4 tetrahedra,  an edgeedge with one Na(15)O4 tetrahedra, and edges with two equivalent Na(7)O4 tetrahedra. In the fourth Na site, Na(4) is bonded to one O(14), one O(15), one O(5), and one O(8) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(17)O4 tetrahedra, corners with two equivalent Na(20)O4 tetrahedra, corners with two equivalent Na(21)O4 tetrahedra, corners with two equivalent Na(24)O4 tetrahedra,  an edgeedge with one Na(11)O4 tetrahedra,  an edgeedge with one Na(14)O4 tetrahedra,  an edgeedge with one Na(16)O4 tetrahedra,  an edgeedge with one Na(9)O4 tetrahedra, and edges with two equivalent Na(8)O4 tetrahedra. In the fifth Na site, Na(5) is bonded to one O(10), one O(11), one O(2), and one O(3) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(12)O4 tetrahedra, corners with two equivalent Na(13)O4 tetrahedra, corners with two equivalent Na(16)O4 tetrahedra, corners with two equivalent Na(9)O4 tetrahedra,  an edgeedge with one Na(17)O4 tetrahedra,  an edgeedge with one Na(19)O4 tetrahedra,  an edgeedge with one Na(22)O4 tetrahedra,  an edgeedge with one Na(24)O4 tetrahedra, and edges with two equivalent Na(1)O4 tetrahedra. In the sixth Na site, Na(6) is bonded to one O(1), one O(12), one O(4), and one O(9) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(10)O4 tetrahedra, corners with two equivalent Na(11)O4 tetrahedra, corners with two equivalent Na(14)O4 tetrahedra, corners with two equivalent Na(15)O4 tetrahedra,  an edgeedge with one Na(18)O4 tetrahedra,  an edgeedge with one Na(20)O4 tetrahedra,  an edgeedge with one Na(21)O4 tetrahedra,  an edgeedge with one Na(23)O4 tetrahedra, and edges with two equivalent Na(2)O4 tetrahedra. In the seventh Na site, Na(7) is bonded to one O(13), one O(16), one O(6), and one O(7) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(10)O4 tetrahedra, corners with two equivalent Na(12)O4 tetrahedra, corners with two equivalent Na(13)O4 tetrahedra, corners with two equivalent Na(15)O4 tetrahedra,  an edgeedge with one Na(18)O4 tetrahedra,  an edgeedge with one Na(19)O4 tetrahedra,  an edgeedge with one Na(22)O4 tetrahedra,  an edgeedge with one Na(23)O4 tetrahedra, and edges with two equivalent Na(3)O4 tetrahedra. In the eighth Na site, Na(8) is bonded to one O(14), one O(15), one O(5), and one O(8) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(11)O4 tetrahedra, corners with two equivalent Na(14)O4 tetrahedra, corners with two equivalent Na(16)O4 tetrahedra, corners with two equivalent Na(9)O4 tetrahedra,  an edgeedge with one Na(17)O4 tetrahedra,  an edgeedge with one Na(20)O4 tetrahedra,  an edgeedge with one Na(21)O4 tetrahedra,  an edgeedge with one Na(24)O4 tetrahedra, and edges with two equivalent Na(4)O4 tetrahedra. In the ninth Na site, Na(9) is bonded to one O(11), one O(15), one O(2), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(24)O4 tetrahedra. In the tenth Na site, Na(10) is bonded to one O(1), one O(12), one O(16), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(23)O4 tetrahedra. In the eleventh Na site, Na(11) is bonded to one O(1), one O(15), one O(5), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(21)O4 tetrahedra. In the twelfth Na site, Na(12) is bonded to one O(10), one O(16), one O(2), and one O(6) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(22)O4 tetrahedra. In the thirteenth Na site, Na(13) is bonded to one O(11), one O(13), one O(3), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(19)O4 tetrahedra. In the fourteenth Na site, Na(14) is bonded to one O(12), one O(14), one O(4), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(20)O4 tetrahedra. In the fifteenth Na site, Na(15) is bonded to one O(13), one O(4), one O(6), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(18)O4 tetrahedra. In the sixteenth Na site, Na(16) is bonded to one O(10), one O(14), one O(3), and one O(5) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(17)O4 tetrahedra. In the seventeenth Na site, Na(17) is bonded to one O(10), one O(14), one O(3), and one O(5) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(16)O4 tetrahedra. In the eighteenth Na site, Na(18) is bonded to one O(13), one O(4), one O(6), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(15)O4 tetrahedra. In the nineteenth Na site, Na(19) is bonded to one O(11), one O(13), one O(3), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(13)O4 tetrahedra. In the twentieth Na site, Na(20) is bonded to one O(12), one O(14), one O(4), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(14)O4 tetrahedra. In the twenty-first Na site, Na(21) is bonded to one O(1), one O(15), one O(5), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(11)O4 tetrahedra. In the twenty-second Na site, Na(22) is bonded to one O(10), one O(16), one O(2), and one O(6) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(12)O4 tetrahedra. In the twenty-third Na site, Na(23) is bonded to one O(1), one O(12), one O(16), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(10)O4 tetrahedra. In the twenty-fourth Na site, Na(24) is bonded to one O(11), one O(15), one O(2), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(9)O4 tetrahedra. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(12), one O(14), and one O(16) atom to form distorted NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(10)O4 tetrahedra, corners with two equivalent Na(12)O4 tetrahedra, corners with two equivalent Na(14)O4 tetrahedra, corners with two equivalent Na(16)O4 tetrahedra,  an edgeedge with one Na(17)O4 tetrahedra,  an edgeedge with one Na(20)O4 tetrahedra,  an edgeedge with one Na(22)O4 tetrahedra, and  an edgeedge with one Na(23)O4 tetrahedra. In the second Ni site, Ni(2) is bonded to one O(11), one O(13), one O(15), and one O(9) atom to form distorted NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(11)O4 tetrahedra, corners with two equivalent Na(13)O4 tetrahedra, corners with two equivalent Na(15)O4 tetrahedra, corners with two equivalent Na(9)O4 tetrahedra,  an edgeedge with one Na(18)O4 tetrahedra,  an edgeedge with one Na(19)O4 tetrahedra,  an edgeedge with one Na(21)O4 tetrahedra, and  an edgeedge with one Na(24)O4 tetrahedra. In the third Ni site, Ni(3) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(17)O4 tetrahedra, corners with two equivalent Na(19)O4 tetrahedra, corners with two equivalent Na(21)O4 tetrahedra, corners with two equivalent Na(23)O4 tetrahedra,  an edgeedge with one Na(10)O4 tetrahedra,  an edgeedge with one Na(11)O4 tetrahedra,  an edgeedge with one Na(13)O4 tetrahedra, and  an edgeedge with one Na(16)O4 tetrahedra. In the fourth Ni site, Ni(4) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(18)O4 tetrahedra, corners with two equivalent Na(20)O4 tetrahedra, corners with two equivalent Na(22)O4 tetrahedra, corners with two equivalent Na(24)O4 tetrahedra,  an edgeedge with one Na(12)O4 tetrahedra,  an edgeedge with one Na(14)O4 tetrahedra,  an edgeedge with one Na(15)O4 tetrahedra, and  an edgeedge with one Na(9)O4 tetrahedra. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded to one Na(10), one Na(11), one Na(2), one Na(21), one Na(23), one Na(6), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the second O site, O(2) is bonded to one Na(1), one Na(12), one Na(22), one Na(24), one Na(5), one Na(9), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the third O site, O(3) is bonded to one Na(1), one Na(13), one Na(16), one Na(17), one Na(19), one Na(5), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fourth O site, O(4) is bonded to one Na(14), one Na(15), one Na(18), one Na(2), one Na(20), one Na(6), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fifth O site, O(5) is bonded to one Na(11), one Na(16), one Na(17), one Na(21), one Na(4), one Na(8), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the sixth O site, O(6) is bonded to one Na(12), one Na(15), one Na(18), one Na(22), one Na(3), one Na(7), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the seventh O site, O(7) is bonded to one Na(10), one Na(13), one Na(19), one Na(23), one Na(3), one Na(7), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the eighth O site, O(8) is bonded to one Na(14), one Na(20), one Na(24), one Na(4), one Na(8), one Na(9), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the ninth O site, O(9) is bonded to one Na(11), one Na(15), one Na(18), one Na(2), one Na(21), one Na(6), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the tenth O site, O(10) is bonded to one Na(1), one Na(12), one Na(16), one Na(17), one Na(22), one Na(5), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the eleventh O site, O(11) is bonded to one Na(1), one Na(13), one Na(19), one Na(24), one Na(5), one Na(9), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the twelfth O site, O(12) is bonded to one Na(10), one Na(14), one Na(2), one Na(20), one Na(23), one Na(6), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the thirteenth O site, O(13) is bonded to one Na(13), one Na(15), one Na(18), one Na(19), one Na(3), one Na(7), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fourteenth O site, O(14) is bonded to one Na(14), one Na(16), one Na(17), one Na(20), one Na(4), one Na(8), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fifteenth O site, O(15) is bonded to one Na(11), one Na(21), one Na(24), one Na(4), one Na(8), one Na(9), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the sixteenth O site, O(16) is bonded to one Na(10), one Na(12), one Na(22), one Na(23), one Na(3), one Na(7), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids.
Na6NiO4 crystallizes in the triclinic P1 space group. There are twenty-four inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(10), one O(11), one O(2), and one O(3) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(17)O4 tetrahedra, corners with two equivalent Na(19)O4 tetrahedra, corners with two equivalent Na(22)O4 tetrahedra, corners with two equivalent Na(24)O4 tetrahedra,  an edgeedge with one Na(12)O4 tetrahedra,  an edgeedge with one Na(13)O4 tetrahedra,  an edgeedge with one Na(16)O4 tetrahedra,  an edgeedge with one Na(9)O4 tetrahedra, and edges with two equivalent Na(5)O4 tetrahedra. The Na(1)-O(10) bond length is 2.29 Å. The Na(1)-O(11) bond length is 2.28 Å. The Na(1)-O(2) bond length is 2.43 Å. The Na(1)-O(3) bond length is 2.40 Å. In the second Na site, Na(2) is bonded to one O(1), one O(12), one O(4), and one O(9) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(18)O4 tetrahedra, corners with two equivalent Na(20)O4 tetrahedra, corners with two equivalent Na(21)O4 tetrahedra, corners with two equivalent Na(23)O4 tetrahedra,  an edgeedge with one Na(10)O4 tetrahedra,  an edgeedge with one Na(11)O4 tetrahedra,  an edgeedge with one Na(14)O4 tetrahedra,  an edgeedge with one Na(15)O4 tetrahedra, and edges with two equivalent Na(6)O4 tetrahedra. The Na(2)-O(1) bond length is 2.40 Å. The Na(2)-O(12) bond length is 2.29 Å. The Na(2)-O(4) bond length is 2.43 Å. The Na(2)-O(9) bond length is 2.28 Å. In the third Na site, Na(3) is bonded to one O(13), one O(16), one O(6), and one O(7) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(18)O4 tetrahedra, corners with two equivalent Na(19)O4 tetrahedra, corners with two equivalent Na(22)O4 tetrahedra, corners with two equivalent Na(23)O4 tetrahedra,  an edgeedge with one Na(10)O4 tetrahedra,  an edgeedge with one Na(12)O4 tetrahedra,  an edgeedge with one Na(13)O4 tetrahedra,  an edgeedge with one Na(15)O4 tetrahedra, and edges with two equivalent Na(7)O4 tetrahedra. The Na(3)-O(13) bond length is 2.28 Å. The Na(3)-O(16) bond length is 2.28 Å. The Na(3)-O(6) bond length is 2.40 Å. The Na(3)-O(7) bond length is 2.44 Å. In the fourth Na site, Na(4) is bonded to one O(14), one O(15), one O(5), and one O(8) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(17)O4 tetrahedra, corners with two equivalent Na(20)O4 tetrahedra, corners with two equivalent Na(21)O4 tetrahedra, corners with two equivalent Na(24)O4 tetrahedra,  an edgeedge with one Na(11)O4 tetrahedra,  an edgeedge with one Na(14)O4 tetrahedra,  an edgeedge with one Na(16)O4 tetrahedra,  an edgeedge with one Na(9)O4 tetrahedra, and edges with two equivalent Na(8)O4 tetrahedra. The Na(4)-O(14) bond length is 2.28 Å. The Na(4)-O(15) bond length is 2.28 Å. The Na(4)-O(5) bond length is 2.44 Å. The Na(4)-O(8) bond length is 2.40 Å. In the fifth Na site, Na(5) is bonded to one O(10), one O(11), one O(2), and one O(3) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(12)O4 tetrahedra, corners with two equivalent Na(13)O4 tetrahedra, corners with two equivalent Na(16)O4 tetrahedra, corners with two equivalent Na(9)O4 tetrahedra,  an edgeedge with one Na(17)O4 tetrahedra,  an edgeedge with one Na(19)O4 tetrahedra,  an edgeedge with one Na(22)O4 tetrahedra,  an edgeedge with one Na(24)O4 tetrahedra, and edges with two equivalent Na(1)O4 tetrahedra. The Na(5)-O(10) bond length is 2.45 Å. The Na(5)-O(11) bond length is 2.39 Å. The Na(5)-O(2) bond length is 2.28 Å. The Na(5)-O(3) bond length is 2.28 Å. In the sixth Na site, Na(6) is bonded to one O(1), one O(12), one O(4), and one O(9) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(10)O4 tetrahedra, corners with two equivalent Na(11)O4 tetrahedra, corners with two equivalent Na(14)O4 tetrahedra, corners with two equivalent Na(15)O4 tetrahedra,  an edgeedge with one Na(18)O4 tetrahedra,  an edgeedge with one Na(20)O4 tetrahedra,  an edgeedge with one Na(21)O4 tetrahedra,  an edgeedge with one Na(23)O4 tetrahedra, and edges with two equivalent Na(2)O4 tetrahedra. The Na(6)-O(1) bond length is 2.28 Å. The Na(6)-O(12) bond length is 2.45 Å. The Na(6)-O(4) bond length is 2.28 Å. The Na(6)-O(9) bond length is 2.39 Å. In the seventh Na site, Na(7) is bonded to one O(13), one O(16), one O(6), and one O(7) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(10)O4 tetrahedra, corners with two equivalent Na(12)O4 tetrahedra, corners with two equivalent Na(13)O4 tetrahedra, corners with two equivalent Na(15)O4 tetrahedra,  an edgeedge with one Na(18)O4 tetrahedra,  an edgeedge with one Na(19)O4 tetrahedra,  an edgeedge with one Na(22)O4 tetrahedra,  an edgeedge with one Na(23)O4 tetrahedra, and edges with two equivalent Na(3)O4 tetrahedra. The Na(7)-O(13) bond length is 2.44 Å. The Na(7)-O(16) bond length is 2.39 Å. The Na(7)-O(6) bond length is 2.28 Å. The Na(7)-O(7) bond length is 2.29 Å. In the eighth Na site, Na(8) is bonded to one O(14), one O(15), one O(5), and one O(8) atom to form NaO4 tetrahedra that share  a cornercorner with one Ni(1)O4 tetrahedra,  a cornercorner with one Ni(2)O4 tetrahedra,  a cornercorner with one Ni(3)O4 tetrahedra,  a cornercorner with one Ni(4)O4 tetrahedra, corners with two equivalent Na(11)O4 tetrahedra, corners with two equivalent Na(14)O4 tetrahedra, corners with two equivalent Na(16)O4 tetrahedra, corners with two equivalent Na(9)O4 tetrahedra,  an edgeedge with one Na(17)O4 tetrahedra,  an edgeedge with one Na(20)O4 tetrahedra,  an edgeedge with one Na(21)O4 tetrahedra,  an edgeedge with one Na(24)O4 tetrahedra, and edges with two equivalent Na(4)O4 tetrahedra. The Na(8)-O(14) bond length is 2.39 Å. The Na(8)-O(15) bond length is 2.45 Å. The Na(8)-O(5) bond length is 2.28 Å. The Na(8)-O(8) bond length is 2.28 Å. In the ninth Na site, Na(9) is bonded to one O(11), one O(15), one O(2), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(24)O4 tetrahedra. The Na(9)-O(11) bond length is 2.39 Å. The Na(9)-O(15) bond length is 2.37 Å. The Na(9)-O(2) bond length is 2.39 Å. The Na(9)-O(8) bond length is 2.37 Å. In the tenth Na site, Na(10) is bonded to one O(1), one O(12), one O(16), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(23)O4 tetrahedra. The Na(10)-O(1) bond length is 2.38 Å. The Na(10)-O(12) bond length is 2.38 Å. The Na(10)-O(16) bond length is 2.40 Å. The Na(10)-O(7) bond length is 2.38 Å. In the eleventh Na site, Na(11) is bonded to one O(1), one O(15), one O(5), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(21)O4 tetrahedra. The Na(11)-O(1) bond length is 2.37 Å. The Na(11)-O(15) bond length is 2.38 Å. The Na(11)-O(5) bond length is 2.39 Å. The Na(11)-O(9) bond length is 2.39 Å. In the twelfth Na site, Na(12) is bonded to one O(10), one O(16), one O(2), and one O(6) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(22)O4 tetrahedra. The Na(12)-O(10) bond length is 2.38 Å. The Na(12)-O(16) bond length is 2.40 Å. The Na(12)-O(2) bond length is 2.39 Å. The Na(12)-O(6) bond length is 2.37 Å. In the thirteenth Na site, Na(13) is bonded to one O(11), one O(13), one O(3), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(19)O4 tetrahedra. The Na(13)-O(11) bond length is 2.39 Å. The Na(13)-O(13) bond length is 2.38 Å. The Na(13)-O(3) bond length is 2.38 Å. The Na(13)-O(7) bond length is 2.39 Å. In the fourteenth Na site, Na(14) is bonded to one O(12), one O(14), one O(4), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(20)O4 tetrahedra. The Na(14)-O(12) bond length is 2.38 Å. The Na(14)-O(14) bond length is 2.40 Å. The Na(14)-O(4) bond length is 2.40 Å. The Na(14)-O(8) bond length is 2.37 Å. In the fifteenth Na site, Na(15) is bonded to one O(13), one O(4), one O(6), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(6)O4 tetrahedra, corners with two equivalent Na(7)O4 tetrahedra, corners with two equivalent Ni(2)O4 tetrahedra,  an edgeedge with one Na(2)O4 tetrahedra,  an edgeedge with one Na(3)O4 tetrahedra,  an edgeedge with one Ni(4)O4 tetrahedra, and edges with two equivalent Na(18)O4 tetrahedra. The Na(15)-O(13) bond length is 2.39 Å. The Na(15)-O(4) bond length is 2.39 Å. The Na(15)-O(6) bond length is 2.37 Å. The Na(15)-O(9) bond length is 2.40 Å. In the sixteenth Na site, Na(16) is bonded to one O(10), one O(14), one O(3), and one O(5) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(5)O4 tetrahedra, corners with two equivalent Na(8)O4 tetrahedra, corners with two equivalent Ni(1)O4 tetrahedra,  an edgeedge with one Na(1)O4 tetrahedra,  an edgeedge with one Na(4)O4 tetrahedra,  an edgeedge with one Ni(3)O4 tetrahedra, and edges with two equivalent Na(17)O4 tetrahedra. The Na(16)-O(10) bond length is 2.38 Å. The Na(16)-O(14) bond length is 2.40 Å. The Na(16)-O(3) bond length is 2.37 Å. The Na(16)-O(5) bond length is 2.39 Å. In the seventeenth Na site, Na(17) is bonded to one O(10), one O(14), one O(3), and one O(5) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(16)O4 tetrahedra. The Na(17)-O(10) bond length is 2.39 Å. The Na(17)-O(14) bond length is 2.37 Å. The Na(17)-O(3) bond length is 2.39 Å. The Na(17)-O(5) bond length is 2.39 Å. In the eighteenth Na site, Na(18) is bonded to one O(13), one O(4), one O(6), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(15)O4 tetrahedra. The Na(18)-O(13) bond length is 2.39 Å. The Na(18)-O(4) bond length is 2.39 Å. The Na(18)-O(6) bond length is 2.39 Å. The Na(18)-O(9) bond length is 2.37 Å. In the nineteenth Na site, Na(19) is bonded to one O(11), one O(13), one O(3), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(13)O4 tetrahedra. The Na(19)-O(11) bond length is 2.37 Å. The Na(19)-O(13) bond length is 2.39 Å. The Na(19)-O(3) bond length is 2.39 Å. The Na(19)-O(7) bond length is 2.39 Å. In the twentieth Na site, Na(20) is bonded to one O(12), one O(14), one O(4), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(14)O4 tetrahedra. The Na(20)-O(12) bond length is 2.39 Å. The Na(20)-O(14) bond length is 2.38 Å. The Na(20)-O(4) bond length is 2.39 Å. The Na(20)-O(8) bond length is 2.39 Å. In the twenty-first Na site, Na(21) is bonded to one O(1), one O(15), one O(5), and one O(9) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(11)O4 tetrahedra. The Na(21)-O(1) bond length is 2.39 Å. The Na(21)-O(15) bond length is 2.40 Å. The Na(21)-O(5) bond length is 2.38 Å. The Na(21)-O(9) bond length is 2.37 Å. In the twenty-second Na site, Na(22) is bonded to one O(10), one O(16), one O(2), and one O(6) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(10)O4 tetrahedra,  a cornercorner with one Na(15)O4 tetrahedra,  a cornercorner with one Na(16)O4 tetrahedra,  a cornercorner with one Na(17)O4 tetrahedra,  a cornercorner with one Na(18)O4 tetrahedra,  a cornercorner with one Na(23)O4 tetrahedra,  a cornercorner with one Na(24)O4 tetrahedra,  a cornercorner with one Na(9)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(12)O4 tetrahedra. The Na(22)-O(10) bond length is 2.39 Å. The Na(22)-O(16) bond length is 2.37 Å. The Na(22)-O(2) bond length is 2.39 Å. The Na(22)-O(6) bond length is 2.39 Å. In the twenty-third Na site, Na(23) is bonded to one O(1), one O(12), one O(16), and one O(7) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(2)O4 tetrahedra, corners with two equivalent Na(3)O4 tetrahedra, corners with two equivalent Ni(3)O4 tetrahedra,  an edgeedge with one Na(6)O4 tetrahedra,  an edgeedge with one Na(7)O4 tetrahedra,  an edgeedge with one Ni(1)O4 tetrahedra, and edges with two equivalent Na(10)O4 tetrahedra. The Na(23)-O(1) bond length is 2.39 Å. The Na(23)-O(12) bond length is 2.39 Å. The Na(23)-O(16) bond length is 2.38 Å. The Na(23)-O(7) bond length is 2.39 Å. In the twenty-fourth Na site, Na(24) is bonded to one O(11), one O(15), one O(2), and one O(8) atom to form distorted NaO4 tetrahedra that share  a cornercorner with one Na(11)O4 tetrahedra,  a cornercorner with one Na(12)O4 tetrahedra,  a cornercorner with one Na(13)O4 tetrahedra,  a cornercorner with one Na(14)O4 tetrahedra,  a cornercorner with one Na(19)O4 tetrahedra,  a cornercorner with one Na(20)O4 tetrahedra,  a cornercorner with one Na(21)O4 tetrahedra,  a cornercorner with one Na(22)O4 tetrahedra, corners with two equivalent Na(1)O4 tetrahedra, corners with two equivalent Na(4)O4 tetrahedra, corners with two equivalent Ni(4)O4 tetrahedra,  an edgeedge with one Na(5)O4 tetrahedra,  an edgeedge with one Na(8)O4 tetrahedra,  an edgeedge with one Ni(2)O4 tetrahedra, and edges with two equivalent Na(9)O4 tetrahedra. The Na(24)-O(11) bond length is 2.37 Å. The Na(24)-O(15) bond length is 2.39 Å. The Na(24)-O(2) bond length is 2.39 Å. The Na(24)-O(8) bond length is 2.39 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(10), one O(12), one O(14), and one O(16) atom to form distorted NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(10)O4 tetrahedra, corners with two equivalent Na(12)O4 tetrahedra, corners with two equivalent Na(14)O4 tetrahedra, corners with two equivalent Na(16)O4 tetrahedra,  an edgeedge with one Na(17)O4 tetrahedra,  an edgeedge with one Na(20)O4 tetrahedra,  an edgeedge with one Na(22)O4 tetrahedra, and  an edgeedge with one Na(23)O4 tetrahedra. The Ni(1)-O(10) bond length is 2.07 Å. The Ni(1)-O(12) bond length is 2.07 Å. The Ni(1)-O(14) bond length is 2.09 Å. The Ni(1)-O(16) bond length is 2.09 Å. In the second Ni site, Ni(2) is bonded to one O(11), one O(13), one O(15), and one O(9) atom to form distorted NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(11)O4 tetrahedra, corners with two equivalent Na(13)O4 tetrahedra, corners with two equivalent Na(15)O4 tetrahedra, corners with two equivalent Na(9)O4 tetrahedra,  an edgeedge with one Na(18)O4 tetrahedra,  an edgeedge with one Na(19)O4 tetrahedra,  an edgeedge with one Na(21)O4 tetrahedra, and  an edgeedge with one Na(24)O4 tetrahedra. The Ni(2)-O(11) bond length is 2.09 Å. The Ni(2)-O(13) bond length is 2.07 Å. The Ni(2)-O(15) bond length is 2.06 Å. The Ni(2)-O(9) bond length is 2.10 Å. In the third Ni site, Ni(3) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(17)O4 tetrahedra, corners with two equivalent Na(19)O4 tetrahedra, corners with two equivalent Na(21)O4 tetrahedra, corners with two equivalent Na(23)O4 tetrahedra,  an edgeedge with one Na(10)O4 tetrahedra,  an edgeedge with one Na(11)O4 tetrahedra,  an edgeedge with one Na(13)O4 tetrahedra, and  an edgeedge with one Na(16)O4 tetrahedra. The Ni(3)-O(1) bond length is 2.09 Å. The Ni(3)-O(3) bond length is 2.09 Å. The Ni(3)-O(5) bond length is 2.07 Å. The Ni(3)-O(7) bond length is 2.07 Å. In the fourth Ni site, Ni(4) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form NiO4 tetrahedra that share  a cornercorner with one Na(1)O4 tetrahedra,  a cornercorner with one Na(2)O4 tetrahedra,  a cornercorner with one Na(3)O4 tetrahedra,  a cornercorner with one Na(4)O4 tetrahedra,  a cornercorner with one Na(5)O4 tetrahedra,  a cornercorner with one Na(6)O4 tetrahedra,  a cornercorner with one Na(7)O4 tetrahedra,  a cornercorner with one Na(8)O4 tetrahedra, corners with two equivalent Na(18)O4 tetrahedra, corners with two equivalent Na(20)O4 tetrahedra, corners with two equivalent Na(22)O4 tetrahedra, corners with two equivalent Na(24)O4 tetrahedra,  an edgeedge with one Na(12)O4 tetrahedra,  an edgeedge with one Na(14)O4 tetrahedra,  an edgeedge with one Na(15)O4 tetrahedra, and  an edgeedge with one Na(9)O4 tetrahedra. The Ni(4)-O(2) bond length is 2.06 Å. The Ni(4)-O(4) bond length is 2.07 Å. The Ni(4)-O(6) bond length is 2.09 Å. The Ni(4)-O(8) bond length is 2.09 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded to one Na(10), one Na(11), one Na(2), one Na(21), one Na(23), one Na(6), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the second O site, O(2) is bonded to one Na(1), one Na(12), one Na(22), one Na(24), one Na(5), one Na(9), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the third O site, O(3) is bonded to one Na(1), one Na(13), one Na(16), one Na(17), one Na(19), one Na(5), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fourth O site, O(4) is bonded to one Na(14), one Na(15), one Na(18), one Na(2), one Na(20), one Na(6), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fifth O site, O(5) is bonded to one Na(11), one Na(16), one Na(17), one Na(21), one Na(4), one Na(8), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the sixth O site, O(6) is bonded to one Na(12), one Na(15), one Na(18), one Na(22), one Na(3), one Na(7), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the seventh O site, O(7) is bonded to one Na(10), one Na(13), one Na(19), one Na(23), one Na(3), one Na(7), and one Ni(3) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the eighth O site, O(8) is bonded to one Na(14), one Na(20), one Na(24), one Na(4), one Na(8), one Na(9), and one Ni(4) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the ninth O site, O(9) is bonded to one Na(11), one Na(15), one Na(18), one Na(2), one Na(21), one Na(6), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the tenth O site, O(10) is bonded to one Na(1), one Na(12), one Na(16), one Na(17), one Na(22), one Na(5), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the eleventh O site, O(11) is bonded to one Na(1), one Na(13), one Na(19), one Na(24), one Na(5), one Na(9), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the twelfth O site, O(12) is bonded to one Na(10), one Na(14), one Na(2), one Na(20), one Na(23), one Na(6), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the thirteenth O site, O(13) is bonded to one Na(13), one Na(15), one Na(18), one Na(19), one Na(3), one Na(7), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fourteenth O site, O(14) is bonded to one Na(14), one Na(16), one Na(17), one Na(20), one Na(4), one Na(8), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the fifteenth O site, O(15) is bonded to one Na(11), one Na(21), one Na(24), one Na(4), one Na(8), one Na(9), and one Ni(2) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids. In the sixteenth O site, O(16) is bonded to one Na(10), one Na(12), one Na(22), one Na(23), one Na(3), one Na(7), and one Ni(1) atom to form a mixture of distorted corner and edge-sharing ONa6Ni pentagonal bipyramids.