The crystal structure described by Na4W4O15 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(7), one O(8), and two equivalent O(6) atoms. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(4), one O(8), and two equivalent O(3) atoms to form NaO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with three equivalent W(2)O6 octahedra, and  an edgeedge with one Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. There are two inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second W site, W(2) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with three equivalent Na(2)O6 octahedra and  an edgeedge with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-62°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Na(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one W(1) atom. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), and one W(2) atom to form distorted ONa3W trigonal pyramids that share  a cornercorner with one O(6)Na2W2 trigonal pyramid,  an edgeedge with one O(6)Na2W2 trigonal pyramid, and  an edgeedge with one O(3)Na3W trigonal pyramid. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Na(2), one W(1), and one W(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one W(1) and two equivalent W(2) atoms. In the sixth O site, O(6) is bonded to two equivalent Na(1), one W(1), and one W(2) atom to form distorted ONa2W2 trigonal pyramids that share  a cornercorner with one O(3)Na3W trigonal pyramid,  an edgeedge with one O(6)Na2W2 trigonal pyramid, and  an edgeedge with one O(3)Na3W trigonal pyramid. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one W(1), and one W(2) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one W(1) atom. is represented by the CIF file [CIF]
data_Na4W4O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.252
_cell_length_b   7.752
_cell_length_c   8.687
_cell_angle_alpha   111.574
_cell_angle_beta   96.703
_cell_angle_gamma   92.618
_symmetry_Int_Tables_number   1
_cell_volume   325.097
_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  0.747  0.225  0.627  1.0
  Na  Na1  1  0.253  0.775  0.373  1.0
  Na  Na2  1  0.318  0.513  0.814  1.0
  Na  Na3  1  0.682  0.487  0.186  1.0
  W  W4  1  0.187  0.233  0.316  1.0
  W  W5  1  0.813  0.767  0.684  1.0
  W  W6  1  0.346  0.035  0.840  1.0
  W  W7  1  0.654  0.965  0.160  1.0
  O  O8  1  0.000  0.500  0.000  1.0
  O  O9  1  0.133  0.298  0.530  1.0
  O  O10  1  0.867  0.702  0.470  1.0
  O  O11  1  0.492  0.263  0.873  1.0
  O  O12  1  0.508  0.737  0.127  1.0
  O  O13  1  0.145  0.772  0.797  1.0
  O  O14  1  0.855  0.228  0.203  1.0
  O  O15  1  0.330  0.083  0.076  1.0
  O  O16  1  0.670  0.917  0.924  1.0
  O  O17  1  0.498  0.098  0.358  1.0
  O  O18  1  0.502  0.902  0.642  1.0
  O  O19  1  0.017  0.056  0.749  1.0
  O  O20  1  0.983  0.944  0.251  1.0
  O  O21  1  0.325  0.448  0.312  1.0
  O  O22  1  0.675  0.552  0.688  1.0
[/CIF]
.
The crystal structure described by Na4W4O15 crystallizes in the triclinic P-1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(7), one O(8), and two equivalent O(6) atoms. In the second Na site, Na(2) is bonded to one O(1), one O(2), one O(4), one O(8), and two equivalent O(3) atoms to form NaO6 octahedra that share  a cornercorner with one Na(2)O6 octahedra, corners with three equivalent W(2)O6 octahedra, and  an edgeedge with one Na(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-62°. There are two inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. In the second W site, W(2) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with three equivalent Na(2)O6 octahedra and  an edgeedge with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-62°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Na(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one W(1) atom. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), and one W(2) atom to form distorted ONa3W trigonal pyramids that share  a cornercorner with one O(6)Na2W2 trigonal pyramid,  an edgeedge with one O(6)Na2W2 trigonal pyramid, and  an edgeedge with one O(3)Na3W trigonal pyramid. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Na(2), one W(1), and one W(2) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one W(1) and two equivalent W(2) atoms. In the sixth O site, O(6) is bonded to two equivalent Na(1), one W(1), and one W(2) atom to form distorted ONa2W2 trigonal pyramids that share  a cornercorner with one O(3)Na3W trigonal pyramid,  an edgeedge with one O(6)Na2W2 trigonal pyramid, and  an edgeedge with one O(3)Na3W trigonal pyramid. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one W(1), and one W(2) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Na(1), one Na(2), and one W(1) atom. is represented by the CIF file [CIF]
data_Na4W4O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.252
_cell_length_b   7.752
_cell_length_c   8.687
_cell_angle_alpha   111.574
_cell_angle_beta   96.703
_cell_angle_gamma   92.618
_symmetry_Int_Tables_number   1
_cell_volume   325.097
_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  0.747  0.225  0.627  1.0
  Na  Na1  1  0.253  0.775  0.373  1.0
  Na  Na2  1  0.318  0.513  0.814  1.0
  Na  Na3  1  0.682  0.487  0.186  1.0
  W  W4  1  0.187  0.233  0.316  1.0
  W  W5  1  0.813  0.767  0.684  1.0
  W  W6  1  0.346  0.035  0.840  1.0
  W  W7  1  0.654  0.965  0.160  1.0
  O  O8  1  0.000  0.500  0.000  1.0
  O  O9  1  0.133  0.298  0.530  1.0
  O  O10  1  0.867  0.702  0.470  1.0
  O  O11  1  0.492  0.263  0.873  1.0
  O  O12  1  0.508  0.737  0.127  1.0
  O  O13  1  0.145  0.772  0.797  1.0
  O  O14  1  0.855  0.228  0.203  1.0
  O  O15  1  0.330  0.083  0.076  1.0
  O  O16  1  0.670  0.917  0.924  1.0
  O  O17  1  0.498  0.098  0.358  1.0
  O  O18  1  0.502  0.902  0.642  1.0
  O  O19  1  0.017  0.056  0.749  1.0
  O  O20  1  0.983  0.944  0.251  1.0
  O  O21  1  0.325  0.448  0.312  1.0
  O  O22  1  0.675  0.552  0.688  1.0
[/CIF]
.