Na4(WO3)9 crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(3), one O(6), two equivalent O(2), two equivalent O(8), two equivalent O(9), and four equivalent O(4) atoms to form NaO12 cuboctahedra that share corners with two equivalent Na(1)O12 cuboctahedra, corners with five equivalent Na(2)O12 cuboctahedra,  a faceface with one Na(1)O12 cuboctahedra,  a faceface with one W(1)O6 octahedra,  a faceface with one W(5)O6 octahedra, faces with two equivalent W(2)O6 octahedra, faces with two equivalent W(3)O6 octahedra, and faces with two equivalent W(4)O6 octahedra. In the second Na site, Na(2) is bonded to one O(10), one O(6), two equivalent O(1), two equivalent O(5), two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms to form NaO12 cuboctahedra that share corners with five equivalent Na(1)O12 cuboctahedra, corners with five equivalent Na(2)O12 cuboctahedra,  a faceface with one W(2)O6 octahedra, faces with two equivalent W(1)O6 octahedra, faces with two equivalent W(4)O6 octahedra, and faces with three equivalent W(5)O6 octahedra. There are five inequivalent W sites. In the first W site, W(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(9) atoms to form WO6 octahedra that share  a cornercorner with one W(5)O6 octahedra, corners with two equivalent W(4)O6 octahedra, corners with three equivalent W(2)O6 octahedra,  a faceface with one Na(1)O12 cuboctahedra, and faces with two equivalent Na(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-3°. In the second W site, W(2) is bonded to one O(3), one O(6), two equivalent O(1), and two equivalent O(4) atoms to form WO6 octahedra that share  a cornercorner with one W(5)O6 octahedra, corners with two equivalent W(3)O6 octahedra, corners with three equivalent W(1)O6 octahedra,  a faceface with one Na(2)O12 cuboctahedra, and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the third W site, W(3) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form WO6 octahedra that share corners with two equivalent W(4)O6 octahedra, corners with four equivalent W(2)O6 octahedra, and faces with four equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. In the fourth W site, W(4) is bonded to one O(10), one O(2), two equivalent O(8), and two equivalent O(9) atoms to form WO6 octahedra that share  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(4)O6 octahedra, corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(5)O6 octahedra, faces with two equivalent Na(1)O12 cuboctahedra, and faces with two equivalent Na(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the fifth W site, W(5) is bonded to one O(5), one O(6), two equivalent O(7), and two equivalent O(8) atoms to form WO6 octahedra that share  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(2)O6 octahedra, corners with two equivalent W(4)O6 octahedra, corners with two equivalent W(5)O6 octahedra,  a faceface with one Na(1)O12 cuboctahedra, and faces with three equivalent Na(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are ten inequivalent O sites. In the first O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(2), one W(1), and one W(5) atom. In the second O site, O(6) is bonded in a distorted square co-planar geometry to one Na(1), one Na(2), one W(2), and one W(5) atom. In the third O site, O(7) is bonded in a distorted square co-planar geometry to two equivalent Na(2) and two equivalent W(5) atoms. In the fourth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one W(4), and one W(5) atom. In the fifth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one W(1), and one W(4) atom. In the sixth O site, O(10) is bonded in a distorted square co-planar geometry to two equivalent Na(2) and two equivalent W(4) atoms. In the seventh O site, O(1) is bonded in a distorted T-shaped geometry to one Na(2), one W(1), and one W(2) atom. In the eighth O site, O(2) is bonded in a distorted square co-planar geometry to two equivalent Na(1), one W(3), and one W(4) atom. In the ninth O site, O(3) is bonded in a distorted T-shaped geometry to one Na(1), one W(1), and one W(2) atom. In the tenth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one W(2), and one W(3) atom.
Na4(WO3)9 crystallizes in the monoclinic C2/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(3), one O(6), two equivalent O(2), two equivalent O(8), two equivalent O(9), and four equivalent O(4) atoms to form NaO12 cuboctahedra that share corners with two equivalent Na(1)O12 cuboctahedra, corners with five equivalent Na(2)O12 cuboctahedra,  a faceface with one Na(1)O12 cuboctahedra,  a faceface with one W(1)O6 octahedra,  a faceface with one W(5)O6 octahedra, faces with two equivalent W(2)O6 octahedra, faces with two equivalent W(3)O6 octahedra, and faces with two equivalent W(4)O6 octahedra. The Na(1)-O(3) bond length is 2.69 Å. The Na(1)-O(6) bond length is 2.72 Å. Both Na(1)-O(2) bond lengths are 2.71 Å. Both Na(1)-O(8) bond lengths are 2.71 Å. Both Na(1)-O(9) bond lengths are 2.71 Å. All Na(1)-O(4) bond lengths are 2.69 Å. In the second Na site, Na(2) is bonded to one O(10), one O(6), two equivalent O(1), two equivalent O(5), two equivalent O(7), two equivalent O(8), and two equivalent O(9) atoms to form NaO12 cuboctahedra that share corners with five equivalent Na(1)O12 cuboctahedra, corners with five equivalent Na(2)O12 cuboctahedra,  a faceface with one W(2)O6 octahedra, faces with two equivalent W(1)O6 octahedra, faces with two equivalent W(4)O6 octahedra, and faces with three equivalent W(5)O6 octahedra. The Na(2)-O(10) bond length is 2.71 Å. The Na(2)-O(6) bond length is 2.71 Å. Both Na(2)-O(1) bond lengths are 2.69 Å. Both Na(2)-O(5) bond lengths are 2.71 Å. Both Na(2)-O(7) bond lengths are 2.71 Å. Both Na(2)-O(8) bond lengths are 2.72 Å. Both Na(2)-O(9) bond lengths are 2.71 Å. There are five inequivalent W sites. In the first W site, W(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(9) atoms to form WO6 octahedra that share  a cornercorner with one W(5)O6 octahedra, corners with two equivalent W(4)O6 octahedra, corners with three equivalent W(2)O6 octahedra,  a faceface with one Na(1)O12 cuboctahedra, and faces with two equivalent Na(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 1-3°. The W(1)-O(3) bond length is 1.91 Å. The W(1)-O(5) bond length is 1.93 Å. Both W(1)-O(1) bond lengths are 1.90 Å. Both W(1)-O(9) bond lengths are 1.93 Å. In the second W site, W(2) is bonded to one O(3), one O(6), two equivalent O(1), and two equivalent O(4) atoms to form WO6 octahedra that share  a cornercorner with one W(5)O6 octahedra, corners with two equivalent W(3)O6 octahedra, corners with three equivalent W(1)O6 octahedra,  a faceface with one Na(2)O12 cuboctahedra, and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. The W(2)-O(3) bond length is 1.91 Å. The W(2)-O(6) bond length is 1.93 Å. Both W(2)-O(1) bond lengths are 1.91 Å. Both W(2)-O(4) bond lengths are 1.93 Å. In the third W site, W(3) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form WO6 octahedra that share corners with two equivalent W(4)O6 octahedra, corners with four equivalent W(2)O6 octahedra, and faces with four equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. Both W(3)-O(2) bond lengths are 1.92 Å. All W(3)-O(4) bond lengths are 1.92 Å. In the fourth W site, W(4) is bonded to one O(10), one O(2), two equivalent O(8), and two equivalent O(9) atoms to form WO6 octahedra that share  a cornercorner with one W(3)O6 octahedra,  a cornercorner with one W(4)O6 octahedra, corners with two equivalent W(1)O6 octahedra, corners with two equivalent W(5)O6 octahedra, faces with two equivalent Na(1)O12 cuboctahedra, and faces with two equivalent Na(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. The W(4)-O(10) bond length is 1.92 Å. The W(4)-O(2) bond length is 1.92 Å. Both W(4)-O(8) bond lengths are 1.93 Å. Both W(4)-O(9) bond lengths are 1.91 Å. In the fifth W site, W(5) is bonded to one O(5), one O(6), two equivalent O(7), and two equivalent O(8) atoms to form WO6 octahedra that share  a cornercorner with one W(1)O6 octahedra,  a cornercorner with one W(2)O6 octahedra, corners with two equivalent W(4)O6 octahedra, corners with two equivalent W(5)O6 octahedra,  a faceface with one Na(1)O12 cuboctahedra, and faces with three equivalent Na(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-1°. The W(5)-O(5) bond length is 1.92 Å. The W(5)-O(6) bond length is 1.92 Å. Both W(5)-O(7) bond lengths are 1.92 Å. Both W(5)-O(8) bond lengths are 1.92 Å. There are ten inequivalent O sites. In the first O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(2), one W(1), and one W(5) atom. In the second O site, O(6) is bonded in a distorted square co-planar geometry to one Na(1), one Na(2), one W(2), and one W(5) atom. In the third O site, O(7) is bonded in a distorted square co-planar geometry to two equivalent Na(2) and two equivalent W(5) atoms. In the fourth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one W(4), and one W(5) atom. In the fifth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one W(1), and one W(4) atom. In the sixth O site, O(10) is bonded in a distorted square co-planar geometry to two equivalent Na(2) and two equivalent W(4) atoms. In the seventh O site, O(1) is bonded in a distorted T-shaped geometry to one Na(2), one W(1), and one W(2) atom. In the eighth O site, O(2) is bonded in a distorted square co-planar geometry to two equivalent Na(1), one W(3), and one W(4) atom. In the ninth O site, O(3) is bonded in a distorted T-shaped geometry to one Na(1), one W(1), and one W(2) atom. In the tenth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one W(2), and one W(3) atom.