Na4Ni3(SbO5)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with three equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-14°. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NaO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NiO6 octahedra that share corners with four equivalent Na(2)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. In the second Ni site, Ni(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with three equivalent Sb(1)O6 octahedra, and edges with four equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-11°. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(1)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-14°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), one Ni(1), and two equivalent Sb(1) atoms to form ONa2NiSb2 square pyramids that share corners with four equivalent O(3)Na3Ni2Sb octahedra,  a cornercorner with one O(1)Na2NiSb2 square pyramid, corners with four equivalent O(2)Na2Ni2Sb square pyramids, edges with two equivalent O(3)Na3Ni2Sb octahedra, edges with two equivalent O(1)Na2NiSb2 square pyramids, and edges with four equivalent O(2)Na2Ni2Sb square pyramids. The corner-sharing octahedral tilt angles range from 3-5°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(2), and one Sb(1) atom to form ONa2Ni2Sb square pyramids that share corners with two equivalent O(3)Na3Ni2Sb octahedra, corners with two equivalent O(1)Na2NiSb2 square pyramids, corners with five equivalent O(2)Na2Ni2Sb square pyramids, edges with five equivalent O(3)Na3Ni2Sb octahedra,  an edgeedge with one O(2)Na2Ni2Sb square pyramid, and edges with two equivalent O(1)Na2NiSb2 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), two equivalent Ni(2), and one Sb(1) atom to form ONa3Ni2Sb octahedra that share corners with two equivalent O(3)Na3Ni2Sb octahedra, corners with two equivalent O(2)Na2Ni2Sb square pyramids, corners with two equivalent O(1)Na2NiSb2 square pyramids, edges with six equivalent O(3)Na3Ni2Sb octahedra,  an edgeedge with one O(1)Na2NiSb2 square pyramid, and edges with five equivalent O(2)Na2Ni2Sb square pyramids. The corner-sharing octahedral tilt angles range from 3-4°.
Na4Ni3(SbO5)2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra,  an edgeedge with one Na(1)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with three equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-14°. Both Na(1)-O(1) bond lengths are 2.43 Å. Both Na(1)-O(2) bond lengths are 2.47 Å. Both Na(1)-O(3) bond lengths are 2.43 Å. In the second Na site, Na(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NaO6 octahedra that share corners with two equivalent Ni(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, edges with three equivalent Na(1)O6 octahedra, and edges with four equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-15°. Both Na(2)-O(2) bond lengths are 2.41 Å. There are two shorter (2.33 Å) and two longer (2.49 Å) Na(2)-O(3) bond lengths. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NiO6 octahedra that share corners with four equivalent Na(2)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with four equivalent Na(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. Both Ni(1)-O(1) bond lengths are 2.10 Å. All Ni(1)-O(2) bond lengths are 2.13 Å. In the second Ni site, Ni(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NiO6 octahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Na(2)O6 octahedra,  an edgeedge with one Ni(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, edges with three equivalent Sb(1)O6 octahedra, and edges with four equivalent Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-11°. Both Ni(2)-O(2) bond lengths are 2.09 Å. There are two shorter (2.13 Å) and two longer (2.17 Å) Ni(2)-O(3) bond lengths. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with two equivalent Na(2)O6 octahedra, corners with four equivalent Na(1)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, edges with two equivalent Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with three equivalent Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 5-14°. Both Sb(1)-O(1) bond lengths are 2.10 Å. Both Sb(1)-O(2) bond lengths are 2.00 Å. Both Sb(1)-O(3) bond lengths are 2.02 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), one Ni(1), and two equivalent Sb(1) atoms to form ONa2NiSb2 square pyramids that share corners with four equivalent O(3)Na3Ni2Sb octahedra,  a cornercorner with one O(1)Na2NiSb2 square pyramid, corners with four equivalent O(2)Na2Ni2Sb square pyramids, edges with two equivalent O(3)Na3Ni2Sb octahedra, edges with two equivalent O(1)Na2NiSb2 square pyramids, and edges with four equivalent O(2)Na2Ni2Sb square pyramids. The corner-sharing octahedral tilt angles range from 3-5°. In the second O site, O(2) is bonded to one Na(1), one Na(2), one Ni(1), one Ni(2), and one Sb(1) atom to form ONa2Ni2Sb square pyramids that share corners with two equivalent O(3)Na3Ni2Sb octahedra, corners with two equivalent O(1)Na2NiSb2 square pyramids, corners with five equivalent O(2)Na2Ni2Sb square pyramids, edges with five equivalent O(3)Na3Ni2Sb octahedra,  an edgeedge with one O(2)Na2Ni2Sb square pyramid, and edges with two equivalent O(1)Na2NiSb2 square pyramids. The corner-sharing octahedral tilt angles are 4°. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), two equivalent Ni(2), and one Sb(1) atom to form ONa3Ni2Sb octahedra that share corners with two equivalent O(3)Na3Ni2Sb octahedra, corners with two equivalent O(2)Na2Ni2Sb square pyramids, corners with two equivalent O(1)Na2NiSb2 square pyramids, edges with six equivalent O(3)Na3Ni2Sb octahedra,  an edgeedge with one O(1)Na2NiSb2 square pyramid, and edges with five equivalent O(2)Na2Ni2Sb square pyramids. The corner-sharing octahedral tilt angles range from 3-4°.