The compound described by Na16W3(NO3)4 crystallizes in the triclinic P1 space group. There are sixteen inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(10), one O(12), one O(2), one O(3), and one O(7) atom to form distorted NaO5 square pyramids that share corners with two equivalent Na(12)O5 square pyramids,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(14)NO3 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra,  an edgeedge with one Na(10)O5 square pyramid,  an edgeedge with one W(1)NO3 tetrahedra,  an edgeedge with one W(2)NO3 tetrahedra, and  an edgeedge with one Na(13)NO3 trigonal pyramid. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(4), one O(8), and one O(9) atom. In the third Na site, Na(3) is bonded in a 2-coordinate geometry to one O(1), one O(12), one O(4), and one O(5) atom. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(11), one O(2), one O(3), one O(6), and one O(9) atom. In the fifth Na site, Na(5) is bonded to one N(1), one N(4), one O(6), and one O(7) atom to form distorted NaN2O2 tetrahedra that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Na(10)O5 square pyramid,  a cornercorner with one Na(14)NO3 tetrahedra,  a cornercorner with one W(1)NO3 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra, and  a cornercorner with one Na(13)NO3 trigonal pyramid. In the sixth Na site, Na(6) is bonded in a 4-coordinate geometry to one N(2), one N(3), one O(5), and one O(8) atom. In the seventh Na site, Na(7) is bonded to one N(2), one N(3), one O(5), and one O(8) atom to form distorted NaN2O2 tetrahedra that share  a cornercorner with one Na(12)O5 square pyramid,  a cornercorner with one Na(14)NO3 tetrahedra,  a cornercorner with one W(1)NO3 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra, and  a cornercorner with one Na(13)NO3 trigonal pyramid. In the eighth Na site, Na(8) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(4), one O(6), and one O(7) atom. In the ninth Na site, Na(9) is bonded in a 2-coordinate geometry to one O(1), one O(12), one O(3), one O(5), and one O(9) atom. In the tenth Na site, Na(10) is bonded to one O(10), one O(11), one O(2), one O(4), and one O(6) atom to form distorted NaO5 square pyramids that share  a cornercorner with one Na(5)N2O2 tetrahedra, corners with two equivalent W(2)NO3 tetrahedra,  an edgeedge with one Na(1)O5 square pyramid,  an edgeedge with one Na(12)O5 square pyramid,  an edgeedge with one Na(14)NO3 tetrahedra, and  an edgeedge with one W(1)NO3 tetrahedra. In the eleventh Na site, Na(11) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(3), and one O(7) atom. In the twelfth Na site, Na(12) is bonded to one O(12), one O(2), one O(4), one O(8), and one O(9) atom to form distorted NaO5 square pyramids that share corners with two equivalent Na(1)O5 square pyramids,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra,  a cornercorner with one Na(13)NO3 trigonal pyramid,  an edgeedge with one Na(10)O5 square pyramid,  an edgeedge with one Na(14)NO3 tetrahedra, and  an edgeedge with one W(3)NO3 tetrahedra. In the thirteenth Na site, Na(13) is bonded to one N(2), one O(1), one O(12), and one O(7) atom to form distorted NaNO3 trigonal pyramids that share  a cornercorner with one Na(12)O5 square pyramid,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one W(1)NO3 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra, corners with two equivalent W(3)NO3 tetrahedra, and  an edgeedge with one Na(1)O5 square pyramid. In the fourteenth Na site, Na(14) is bonded to one N(1), one O(11), one O(2), and one O(8) atom to form distorted NaNO3 tetrahedra that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra, corners with two equivalent W(2)NO3 tetrahedra,  an edgeedge with one Na(10)O5 square pyramid, and  an edgeedge with one Na(12)O5 square pyramid. In the fifteenth Na site, Na(15) is bonded in a 4-coordinate geometry to one N(4), one O(10), one O(3), and one O(5) atom. In the sixteenth Na site, Na(16) is bonded in a distorted rectangular see-saw-like geometry to one N(3), one O(4), one O(6), and one O(9) atom. There are three inequivalent W sites. In the first W site, W(1) is bonded to one N(2), one O(10), one O(3), and one O(6) atom to form WNO3 tetrahedra that share  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one Na(13)NO3 trigonal pyramid,  an edgeedge with one Na(1)O5 square pyramid, and  an edgeedge with one Na(10)O5 square pyramid. In the second W site, W(2) is bonded to one N(3), one O(11), one O(2), and one O(7) atom to form WNO3 tetrahedra that share  a cornercorner with one Na(12)O5 square pyramid, corners with two equivalent Na(10)O5 square pyramids,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra, corners with two equivalent Na(14)NO3 tetrahedra,  a cornercorner with one Na(13)NO3 trigonal pyramid, and  an edgeedge with one Na(1)O5 square pyramid. In the third W site, W(3) is bonded to one N(4), one O(1), one O(12), and one O(8) atom to form WNO3 tetrahedra that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one Na(14)NO3 tetrahedra, corners with two equivalent Na(13)NO3 trigonal pyramids, and  an edgeedge with one Na(12)O5 square pyramid. There are four inequivalent N sites. In the first N site, N(1) is bonded in a trigonal non-coplanar geometry to one Na(14), one Na(5), and one Na(8) atom. In the second N site, N(2) is bonded to one Na(13), one Na(6), one Na(7), and one W(1) atom to form distorted NNa3W tetrahedra that share  a cornercorner with one O(7)Na5W octahedra,  a cornercorner with one O(10)Na4W square pyramid, and corners with two equivalent O(5)Na5 square pyramids. The corner-sharing octahedral tilt angles are 62°. In the third N site, N(3) is bonded in a rectangular see-saw-like geometry to one Na(16), one Na(6), one Na(7), and one W(2) atom. In the fourth N site, N(4) is bonded in a distorted rectangular see-saw-like geometry to one Na(15), one Na(5), one Na(8), and one W(3) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(11), one Na(13), one Na(2), one Na(3), one Na(9), and one W(3) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(10), one Na(12), one Na(14), one Na(4), and one W(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(11), one Na(15), one Na(4), one Na(9), and one W(1) atom. In the fourth O site, O(4) is bonded to one Na(10), one Na(12), one Na(16), one Na(2), and one Na(3) atom to form ONa5 square pyramids that share  a cornercorner with one O(10)Na4W square pyramid,  a cornercorner with one O(5)Na5 square pyramid,  a cornercorner with one O(9)Na5 trigonal bipyramid,  an edgeedge with one O(11)Na5W octahedra, and  an edgeedge with one O(9)Na5 trigonal bipyramid. In the fifth O site, O(5) is bonded to one Na(15), one Na(3), one Na(6), one Na(7), and one Na(9) atom to form ONa5 square pyramids that share  a cornercorner with one O(10)Na4W square pyramid,  a cornercorner with one O(4)Na5 square pyramid, corners with two equivalent N(2)Na3W tetrahedra, and  a cornercorner with one O(9)Na5 trigonal bipyramid. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(10), one Na(16), one Na(4), one Na(5), one Na(8), and one W(1) atom. In the seventh O site, O(7) is bonded to one Na(1), one Na(11), one Na(13), one Na(5), one Na(8), and one W(2) atom to form distorted ONa5W octahedra that share corners with two equivalent O(10)Na4W square pyramids,  a cornercorner with one N(2)Na3W tetrahedra, and  an edgeedge with one O(11)Na5W octahedra. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Na(12), one Na(14), one Na(2), one Na(6), one Na(7), and one W(3) atom. In the ninth O site, O(9) is bonded to one Na(12), one Na(16), one Na(2), one Na(4), and one Na(9) atom to form ONa5 trigonal bipyramids that share  a cornercorner with one O(4)Na5 square pyramid,  a cornercorner with one O(5)Na5 square pyramid,  an edgeedge with one O(11)Na5W octahedra, and  an edgeedge with one O(4)Na5 square pyramid. In the tenth O site, O(10) is bonded to one Na(1), one Na(10), one Na(11), one Na(15), and one W(1) atom to form ONa4W square pyramids that share corners with two equivalent O(7)Na5W octahedra,  a cornercorner with one O(4)Na5 square pyramid,  a cornercorner with one O(5)Na5 square pyramid,  a cornercorner with one N(2)Na3W tetrahedra, and  an edgeedge with one O(11)Na5W octahedra. The corner-sharing octahedral tilt angles range from 17-23°. In the eleventh O site, O(11) is bonded to one Na(10), one Na(11), one Na(14), one Na(2), one Na(4), and one W(2) atom to form distorted ONa5W octahedra that share  an edgeedge with one O(7)Na5W octahedra,  an edgeedge with one O(10)Na4W square pyramid,  an edgeedge with one O(4)Na5 square pyramid, and  an edgeedge with one O(9)Na5 trigonal bipyramid. In the twelfth O site, O(12) is bonded in a 6-coordinate geometry to one Na(1), one Na(12), one Na(13), one Na(3), one Na(9), and one W(3) atom. is represented by the CIF file [CIF]
data_Na16W3(NO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.870
_cell_length_b   9.032
_cell_length_c   10.020
_cell_angle_alpha   106.987
_cell_angle_beta   89.635
_cell_angle_gamma   102.346
_symmetry_Int_Tables_number   1
_cell_volume   579.842
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Na  Na0  1  0.158  0.608  0.393  1.0
  Na  Na1  1  0.634  0.547  0.880  1.0
  Na  Na2  1  0.370  0.361  0.040  1.0
  Na  Na3  1  0.817  0.366  0.634  1.0
  Na  Na4  1  0.743  0.987  0.486  1.0
  Na  Na5  1  0.259  0.015  0.990  1.0
  Na  Na6  1  0.754  0.030  0.999  1.0
  Na  Na7  1  0.265  0.022  0.516  1.0
  Na  Na8  1  0.803  0.390  0.062  1.0
  Na  Na9  1  0.346  0.432  0.626  1.0
  Na  Na10  1  0.647  0.546  0.376  1.0
  Na  Na11  1  0.157  0.579  0.893  1.0
  Na  Na12  1  0.966  0.815  0.233  1.0
  Na  Na13  1  0.465  0.819  0.752  1.0
  Na  Na14  1  0.536  0.183  0.268  1.0
  Na  Na15  1  0.037  0.216  0.786  1.0
  W  W16  1  0.061  0.247  0.342  1.0
  W  W17  1  0.937  0.754  0.656  1.0
  W  W18  1  0.442  0.758  0.167  1.0
  N  N19  1  0.535  0.044  0.664  1.0
  N  N20  1  0.025  0.075  0.191  1.0
  N  N21  1  0.968  0.927  0.805  1.0
  N  N22  1  0.472  0.933  0.314  1.0
  O  O23  1  0.637  0.646  0.184  1.0
  O  O24  1  0.142  0.646  0.656  1.0
  O  O25  1  0.874  0.372  0.343  1.0
  O  O26  1  0.331  0.393  0.831  1.0
  O  O27  1  0.545  0.192  0.058  1.0
  O  O28  1  0.036  0.185  0.505  1.0
  O  O29  1  0.961  0.810  0.487  1.0
  O  O30  1  0.457  0.805  0.996  1.0
  O  O31  1  0.873  0.419  0.857  1.0
  O  O32  1  0.318  0.379  0.360  1.0
  O  O33  1  0.680  0.623  0.642  1.0
  O  O34  1  0.188  0.637  0.171  1.0
[/CIF]
.
The compound described by Na16W3(NO3)4 crystallizes in the triclinic P1 space group. There are sixteen inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(10), one O(12), one O(2), one O(3), and one O(7) atom to form distorted NaO5 square pyramids that share corners with two equivalent Na(12)O5 square pyramids,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(14)NO3 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra,  an edgeedge with one Na(10)O5 square pyramid,  an edgeedge with one W(1)NO3 tetrahedra,  an edgeedge with one W(2)NO3 tetrahedra, and  an edgeedge with one Na(13)NO3 trigonal pyramid. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(4), one O(8), and one O(9) atom. In the third Na site, Na(3) is bonded in a 2-coordinate geometry to one O(1), one O(12), one O(4), and one O(5) atom. In the fourth Na site, Na(4) is bonded in a 5-coordinate geometry to one O(11), one O(2), one O(3), one O(6), and one O(9) atom. In the fifth Na site, Na(5) is bonded to one N(1), one N(4), one O(6), and one O(7) atom to form distorted NaN2O2 tetrahedra that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Na(10)O5 square pyramid,  a cornercorner with one Na(14)NO3 tetrahedra,  a cornercorner with one W(1)NO3 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra, and  a cornercorner with one Na(13)NO3 trigonal pyramid. In the sixth Na site, Na(6) is bonded in a 4-coordinate geometry to one N(2), one N(3), one O(5), and one O(8) atom. In the seventh Na site, Na(7) is bonded to one N(2), one N(3), one O(5), and one O(8) atom to form distorted NaN2O2 tetrahedra that share  a cornercorner with one Na(12)O5 square pyramid,  a cornercorner with one Na(14)NO3 tetrahedra,  a cornercorner with one W(1)NO3 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra, and  a cornercorner with one Na(13)NO3 trigonal pyramid. In the eighth Na site, Na(8) is bonded in a distorted rectangular see-saw-like geometry to one N(1), one N(4), one O(6), and one O(7) atom. In the ninth Na site, Na(9) is bonded in a 2-coordinate geometry to one O(1), one O(12), one O(3), one O(5), and one O(9) atom. In the tenth Na site, Na(10) is bonded to one O(10), one O(11), one O(2), one O(4), and one O(6) atom to form distorted NaO5 square pyramids that share  a cornercorner with one Na(5)N2O2 tetrahedra, corners with two equivalent W(2)NO3 tetrahedra,  an edgeedge with one Na(1)O5 square pyramid,  an edgeedge with one Na(12)O5 square pyramid,  an edgeedge with one Na(14)NO3 tetrahedra, and  an edgeedge with one W(1)NO3 tetrahedra. In the eleventh Na site, Na(11) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(3), and one O(7) atom. In the twelfth Na site, Na(12) is bonded to one O(12), one O(2), one O(4), one O(8), and one O(9) atom to form distorted NaO5 square pyramids that share corners with two equivalent Na(1)O5 square pyramids,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra,  a cornercorner with one Na(13)NO3 trigonal pyramid,  an edgeedge with one Na(10)O5 square pyramid,  an edgeedge with one Na(14)NO3 tetrahedra, and  an edgeedge with one W(3)NO3 tetrahedra. In the thirteenth Na site, Na(13) is bonded to one N(2), one O(1), one O(12), and one O(7) atom to form distorted NaNO3 trigonal pyramids that share  a cornercorner with one Na(12)O5 square pyramid,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one W(1)NO3 tetrahedra,  a cornercorner with one W(2)NO3 tetrahedra, corners with two equivalent W(3)NO3 tetrahedra, and  an edgeedge with one Na(1)O5 square pyramid. In the fourteenth Na site, Na(14) is bonded to one N(1), one O(11), one O(2), and one O(8) atom to form distorted NaNO3 tetrahedra that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one W(3)NO3 tetrahedra, corners with two equivalent W(2)NO3 tetrahedra,  an edgeedge with one Na(10)O5 square pyramid, and  an edgeedge with one Na(12)O5 square pyramid. In the fifteenth Na site, Na(15) is bonded in a 4-coordinate geometry to one N(4), one O(10), one O(3), and one O(5) atom. In the sixteenth Na site, Na(16) is bonded in a distorted rectangular see-saw-like geometry to one N(3), one O(4), one O(6), and one O(9) atom. There are three inequivalent W sites. In the first W site, W(1) is bonded to one N(2), one O(10), one O(3), and one O(6) atom to form WNO3 tetrahedra that share  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one Na(13)NO3 trigonal pyramid,  an edgeedge with one Na(1)O5 square pyramid, and  an edgeedge with one Na(10)O5 square pyramid. In the second W site, W(2) is bonded to one N(3), one O(11), one O(2), and one O(7) atom to form WNO3 tetrahedra that share  a cornercorner with one Na(12)O5 square pyramid, corners with two equivalent Na(10)O5 square pyramids,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra, corners with two equivalent Na(14)NO3 tetrahedra,  a cornercorner with one Na(13)NO3 trigonal pyramid, and  an edgeedge with one Na(1)O5 square pyramid. In the third W site, W(3) is bonded to one N(4), one O(1), one O(12), and one O(8) atom to form WNO3 tetrahedra that share  a cornercorner with one Na(1)O5 square pyramid,  a cornercorner with one Na(5)N2O2 tetrahedra,  a cornercorner with one Na(7)N2O2 tetrahedra,  a cornercorner with one Na(14)NO3 tetrahedra, corners with two equivalent Na(13)NO3 trigonal pyramids, and  an edgeedge with one Na(12)O5 square pyramid. There are four inequivalent N sites. In the first N site, N(1) is bonded in a trigonal non-coplanar geometry to one Na(14), one Na(5), and one Na(8) atom. In the second N site, N(2) is bonded to one Na(13), one Na(6), one Na(7), and one W(1) atom to form distorted NNa3W tetrahedra that share  a cornercorner with one O(7)Na5W octahedra,  a cornercorner with one O(10)Na4W square pyramid, and corners with two equivalent O(5)Na5 square pyramids. The corner-sharing octahedral tilt angles are 62°. In the third N site, N(3) is bonded in a rectangular see-saw-like geometry to one Na(16), one Na(6), one Na(7), and one W(2) atom. In the fourth N site, N(4) is bonded in a distorted rectangular see-saw-like geometry to one Na(15), one Na(5), one Na(8), and one W(3) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(11), one Na(13), one Na(2), one Na(3), one Na(9), and one W(3) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(10), one Na(12), one Na(14), one Na(4), and one W(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), one Na(11), one Na(15), one Na(4), one Na(9), and one W(1) atom. In the fourth O site, O(4) is bonded to one Na(10), one Na(12), one Na(16), one Na(2), and one Na(3) atom to form ONa5 square pyramids that share  a cornercorner with one O(10)Na4W square pyramid,  a cornercorner with one O(5)Na5 square pyramid,  a cornercorner with one O(9)Na5 trigonal bipyramid,  an edgeedge with one O(11)Na5W octahedra, and  an edgeedge with one O(9)Na5 trigonal bipyramid. In the fifth O site, O(5) is bonded to one Na(15), one Na(3), one Na(6), one Na(7), and one Na(9) atom to form ONa5 square pyramids that share  a cornercorner with one O(10)Na4W square pyramid,  a cornercorner with one O(4)Na5 square pyramid, corners with two equivalent N(2)Na3W tetrahedra, and  a cornercorner with one O(9)Na5 trigonal bipyramid. In the sixth O site, O(6) is bonded in a 6-coordinate geometry to one Na(10), one Na(16), one Na(4), one Na(5), one Na(8), and one W(1) atom. In the seventh O site, O(7) is bonded to one Na(1), one Na(11), one Na(13), one Na(5), one Na(8), and one W(2) atom to form distorted ONa5W octahedra that share corners with two equivalent O(10)Na4W square pyramids,  a cornercorner with one N(2)Na3W tetrahedra, and  an edgeedge with one O(11)Na5W octahedra. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to one Na(12), one Na(14), one Na(2), one Na(6), one Na(7), and one W(3) atom. In the ninth O site, O(9) is bonded to one Na(12), one Na(16), one Na(2), one Na(4), and one Na(9) atom to form ONa5 trigonal bipyramids that share  a cornercorner with one O(4)Na5 square pyramid,  a cornercorner with one O(5)Na5 square pyramid,  an edgeedge with one O(11)Na5W octahedra, and  an edgeedge with one O(4)Na5 square pyramid. In the tenth O site, O(10) is bonded to one Na(1), one Na(10), one Na(11), one Na(15), and one W(1) atom to form ONa4W square pyramids that share corners with two equivalent O(7)Na5W octahedra,  a cornercorner with one O(4)Na5 square pyramid,  a cornercorner with one O(5)Na5 square pyramid,  a cornercorner with one N(2)Na3W tetrahedra, and  an edgeedge with one O(11)Na5W octahedra. The corner-sharing octahedral tilt angles range from 17-23°. In the eleventh O site, O(11) is bonded to one Na(10), one Na(11), one Na(14), one Na(2), one Na(4), and one W(2) atom to form distorted ONa5W octahedra that share  an edgeedge with one O(7)Na5W octahedra,  an edgeedge with one O(10)Na4W square pyramid,  an edgeedge with one O(4)Na5 square pyramid, and  an edgeedge with one O(9)Na5 trigonal bipyramid. In the twelfth O site, O(12) is bonded in a 6-coordinate geometry to one Na(1), one Na(12), one Na(13), one Na(3), one Na(9), and one W(3) atom. is represented by the CIF file [CIF]
data_Na16W3(NO3)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.870
_cell_length_b   9.032
_cell_length_c   10.020
_cell_angle_alpha   106.987
_cell_angle_beta   89.635
_cell_angle_gamma   102.346
_symmetry_Int_Tables_number   1
_cell_volume   579.842
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Na  Na0  1  0.158  0.608  0.393  1.0
  Na  Na1  1  0.634  0.547  0.880  1.0
  Na  Na2  1  0.370  0.361  0.040  1.0
  Na  Na3  1  0.817  0.366  0.634  1.0
  Na  Na4  1  0.743  0.987  0.486  1.0
  Na  Na5  1  0.259  0.015  0.990  1.0
  Na  Na6  1  0.754  0.030  0.999  1.0
  Na  Na7  1  0.265  0.022  0.516  1.0
  Na  Na8  1  0.803  0.390  0.062  1.0
  Na  Na9  1  0.346  0.432  0.626  1.0
  Na  Na10  1  0.647  0.546  0.376  1.0
  Na  Na11  1  0.157  0.579  0.893  1.0
  Na  Na12  1  0.966  0.815  0.233  1.0
  Na  Na13  1  0.465  0.819  0.752  1.0
  Na  Na14  1  0.536  0.183  0.268  1.0
  Na  Na15  1  0.037  0.216  0.786  1.0
  W  W16  1  0.061  0.247  0.342  1.0
  W  W17  1  0.937  0.754  0.656  1.0
  W  W18  1  0.442  0.758  0.167  1.0
  N  N19  1  0.535  0.044  0.664  1.0
  N  N20  1  0.025  0.075  0.191  1.0
  N  N21  1  0.968  0.927  0.805  1.0
  N  N22  1  0.472  0.933  0.314  1.0
  O  O23  1  0.637  0.646  0.184  1.0
  O  O24  1  0.142  0.646  0.656  1.0
  O  O25  1  0.874  0.372  0.343  1.0
  O  O26  1  0.331  0.393  0.831  1.0
  O  O27  1  0.545  0.192  0.058  1.0
  O  O28  1  0.036  0.185  0.505  1.0
  O  O29  1  0.961  0.810  0.487  1.0
  O  O30  1  0.457  0.805  0.996  1.0
  O  O31  1  0.873  0.419  0.857  1.0
  O  O32  1  0.318  0.379  0.360  1.0
  O  O33  1  0.680  0.623  0.642  1.0
  O  O34  1  0.188  0.637  0.171  1.0
[/CIF]
.