The structure described by Na6NbAl3Si2(PO6)4 crystallizes in the triclinic P1 space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to one O(1), one O(11), one O(21), one O(23), one O(3), and one O(9) atom. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to one O(10), one O(12), one O(2), one O(22), one O(24), and one O(4) atom. In the third Na site, Na(3) is bonded in a 8-coordinate geometry to one O(1), one O(13), one O(14), one O(19), one O(2), one O(20), one O(21), and one O(22) atom. In the fourth Na site, Na(4) is bonded in a 8-coordinate geometry to one O(15), one O(16), one O(17), one O(18), one O(23), one O(24), one O(3), and one O(4) atom. In the fifth Na site, Na(5) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(13), one O(24), one O(3), one O(6), and one O(7) atom. In the sixth Na site, Na(6) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(15), one O(22), one O(5), one O(8), and one O(9) atom. Nb(1) is bonded to one O(10), one O(16), one O(19), one O(2), one O(22), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(15), one O(20), one O(21), one O(7), and one O(9) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. In the second Al site, Al(2) is bonded to one O(11), one O(13), one O(18), one O(23), one O(3), and one O(5) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. In the third Al site, Al(3) is bonded to one O(12), one O(14), one O(17), one O(24), one O(4), and one O(6) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(17), one O(2), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-37°. In the second Si site, Si(2) is bonded to one O(11), one O(15), one O(19), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-39°. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(21), one O(22), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-36°. In the second P site, P(2) is bonded to one O(23), one O(24), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-37°. In the third P site, P(3) is bonded to one O(1), one O(10), one O(14), and one O(18) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-37°. In the fourth P site, P(4) is bonded to one O(12), one O(16), one O(20), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-40°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(6), one Al(1), and one P(3) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Na(3), one Nb(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), one Na(4), one Na(5), one Al(2), and one P(4) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Na(2), one Na(4), one Al(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Na(6), one Al(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(5), one Al(3), and one P(1) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(5), one Al(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Na(6), one Nb(1), and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(6), one Al(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Na(6), one Nb(1), and one P(3) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(5), one Al(2), and one Si(2) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Na(5), one Al(3), and one P(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Na(3), one Na(5), one Al(2), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Al(3), and one P(3) atom. In the fifteenth O site, O(15) is bonded in a 4-coordinate geometry to one Na(4), one Na(6), one Al(1), and one Si(2) atom. In the sixteenth O site, O(16) is bonded in a distorted linear geometry to one Na(4), one Nb(1), and one P(4) atom. In the seventeenth O site, O(17) is bonded in a distorted bent 150 degrees geometry to one Na(4), one Al(3), and one Si(1) atom. In the eighteenth O site, O(18) is bonded in a 3-coordinate geometry to one Na(4), one Al(2), and one P(3) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Nb(1), and one Si(2) atom. In the twentieth O site, O(20) is bonded in a 3-coordinate geometry to one Na(3), one Al(1), and one P(4) atom. In the twenty-first O site, O(21) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Al(1), and one P(1) atom. In the twenty-second O site, O(22) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(6), one Nb(1), and one P(1) atom. In the twenty-third O site, O(23) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(4), one Al(2), and one P(2) atom. In the twenty-fourth O site, O(24) is bonded in a 5-coordinate geometry to one Na(2), one Na(4), one Na(5), one Al(3), and one P(2) atom. is represented by the CIF file [CIF]
data_Na6NbAl3Si2(PO6)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.741
_cell_length_b   8.756
_cell_length_c   8.771
_cell_angle_alpha   60.557
_cell_angle_beta   60.737
_cell_angle_gamma   60.149
_symmetry_Int_Tables_number   1
_cell_volume   479.877
_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
  Al  Al0  1  0.858  0.354  0.436  1.0
  Al  Al1  1  0.143  0.647  0.563  1.0
  Al  Al2  1  0.356  0.850  0.940  1.0
  Na  Na3  1  1.000  0.502  0.000  1.0
  Na  Na4  1  0.497  0.994  0.513  1.0
  Na  Na5  1  0.597  0.394  0.263  1.0
  Na  Na6  1  0.391  0.618  0.743  1.0
  Na  Na7  1  0.121  0.263  0.711  1.0
  Na  Na8  1  0.878  0.736  0.292  1.0
  Nb  Nb9  1  0.644  0.146  0.065  1.0
  O  O10  1  0.716  0.576  0.262  1.0
  O  O11  1  0.424  0.269  0.239  1.0
  O  O12  1  0.284  0.421  0.740  1.0
  O  O13  1  0.565  0.736  0.768  1.0
  O  O14  1  0.009  0.866  0.416  1.0
  O  O15  1  0.134  0.017  0.066  1.0
  O  O16  1  0.995  0.134  0.582  1.0
  O  O17  1  0.876  0.978  0.927  1.0
  O  O18  1  0.060  0.440  0.268  1.0
  O  O19  1  0.571  0.908  0.247  1.0
  O  O20  1  0.937  0.564  0.734  1.0
  O  O21  1  0.424  0.083  0.760  1.0
  O  O22  1  0.223  0.494  0.429  1.0
  O  O23  1  0.490  0.790  0.088  1.0
  O  O24  1  0.775  0.506  0.574  1.0
  O  O25  1  0.511  0.206  0.907  1.0
  O  O26  1  0.284  0.641  0.061  1.0
  O  O27  1  0.370  0.707  0.439  1.0
  O  O28  1  0.716  0.364  0.931  1.0
  O  O29  1  0.630  0.284  0.562  1.0
  O  O30  1  0.929  0.227  0.264  1.0
  O  O31  1  0.789  0.054  0.241  1.0
  O  O32  1  0.080  0.771  0.731  1.0
  O  O33  1  0.219  0.946  0.758  1.0
  P  P34  1  0.978  0.039  0.248  1.0
  P  P35  1  0.043  0.957  0.743  1.0
  P  P36  1  0.531  0.745  0.259  1.0
  P  P37  1  0.464  0.248  0.735  1.0
  Si  Si38  1  0.239  0.469  0.249  1.0
  Si  Si39  1  0.752  0.556  0.743  1.0
[/CIF]
.
The structure described by Na6NbAl3Si2(PO6)4 crystallizes in the triclinic P1 space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to one O(1), one O(11), one O(21), one O(23), one O(3), and one O(9) atom. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to one O(10), one O(12), one O(2), one O(22), one O(24), and one O(4) atom. In the third Na site, Na(3) is bonded in a 8-coordinate geometry to one O(1), one O(13), one O(14), one O(19), one O(2), one O(20), one O(21), and one O(22) atom. In the fourth Na site, Na(4) is bonded in a 8-coordinate geometry to one O(15), one O(16), one O(17), one O(18), one O(23), one O(24), one O(3), and one O(4) atom. In the fifth Na site, Na(5) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(13), one O(24), one O(3), one O(6), and one O(7) atom. In the sixth Na site, Na(6) is bonded in a 7-coordinate geometry to one O(1), one O(10), one O(15), one O(22), one O(5), one O(8), and one O(9) atom. Nb(1) is bonded to one O(10), one O(16), one O(19), one O(2), one O(22), and one O(8) atom to form NbO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(15), one O(20), one O(21), one O(7), and one O(9) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. In the second Al site, Al(2) is bonded to one O(11), one O(13), one O(18), one O(23), one O(3), and one O(5) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. In the third Al site, Al(3) is bonded to one O(12), one O(14), one O(17), one O(24), one O(4), and one O(6) atom to form AlO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(17), one O(2), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-37°. In the second Si site, Si(2) is bonded to one O(11), one O(15), one O(19), and one O(4) atom to form SiO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-39°. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(21), one O(22), one O(5), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 22-36°. In the second P site, P(2) is bonded to one O(23), one O(24), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-37°. In the third P site, P(3) is bonded to one O(1), one O(10), one O(14), and one O(18) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-37°. In the fourth P site, P(4) is bonded to one O(12), one O(16), one O(20), and one O(3) atom to form PO4 tetrahedra that share  a cornercorner with one Nb(1)O6 octahedra,  a cornercorner with one Al(1)O6 octahedra,  a cornercorner with one Al(2)O6 octahedra, and  a cornercorner with one Al(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-40°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(6), one Al(1), and one P(3) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Na(3), one Nb(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), one Na(4), one Na(5), one Al(2), and one P(4) atom. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Na(2), one Na(4), one Al(3), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Na(6), one Al(2), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(5), one Al(3), and one P(1) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(5), one Al(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Na(6), one Nb(1), and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(6), one Al(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Na(6), one Nb(1), and one P(3) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(5), one Al(2), and one Si(2) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(2), one Na(5), one Al(3), and one P(4) atom. In the thirteenth O site, O(13) is bonded in a 4-coordinate geometry to one Na(3), one Na(5), one Al(2), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Al(3), and one P(3) atom. In the fifteenth O site, O(15) is bonded in a 4-coordinate geometry to one Na(4), one Na(6), one Al(1), and one Si(2) atom. In the sixteenth O site, O(16) is bonded in a distorted linear geometry to one Na(4), one Nb(1), and one P(4) atom. In the seventeenth O site, O(17) is bonded in a distorted bent 150 degrees geometry to one Na(4), one Al(3), and one Si(1) atom. In the eighteenth O site, O(18) is bonded in a 3-coordinate geometry to one Na(4), one Al(2), and one P(3) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Nb(1), and one Si(2) atom. In the twentieth O site, O(20) is bonded in a 3-coordinate geometry to one Na(3), one Al(1), and one P(4) atom. In the twenty-first O site, O(21) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Al(1), and one P(1) atom. In the twenty-second O site, O(22) is bonded in a 5-coordinate geometry to one Na(2), one Na(3), one Na(6), one Nb(1), and one P(1) atom. In the twenty-third O site, O(23) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(4), one Al(2), and one P(2) atom. In the twenty-fourth O site, O(24) is bonded in a 5-coordinate geometry to one Na(2), one Na(4), one Na(5), one Al(3), and one P(2) atom. is represented by the CIF file [CIF]
data_Na6NbAl3Si2(PO6)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.741
_cell_length_b   8.756
_cell_length_c   8.771
_cell_angle_alpha   60.557
_cell_angle_beta   60.737
_cell_angle_gamma   60.149
_symmetry_Int_Tables_number   1
_cell_volume   479.877
_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
  Al  Al0  1  0.858  0.354  0.436  1.0
  Al  Al1  1  0.143  0.647  0.563  1.0
  Al  Al2  1  0.356  0.850  0.940  1.0
  Na  Na3  1  1.000  0.502  0.000  1.0
  Na  Na4  1  0.497  0.994  0.513  1.0
  Na  Na5  1  0.597  0.394  0.263  1.0
  Na  Na6  1  0.391  0.618  0.743  1.0
  Na  Na7  1  0.121  0.263  0.711  1.0
  Na  Na8  1  0.878  0.736  0.292  1.0
  Nb  Nb9  1  0.644  0.146  0.065  1.0
  O  O10  1  0.716  0.576  0.262  1.0
  O  O11  1  0.424  0.269  0.239  1.0
  O  O12  1  0.284  0.421  0.740  1.0
  O  O13  1  0.565  0.736  0.768  1.0
  O  O14  1  0.009  0.866  0.416  1.0
  O  O15  1  0.134  0.017  0.066  1.0
  O  O16  1  0.995  0.134  0.582  1.0
  O  O17  1  0.876  0.978  0.927  1.0
  O  O18  1  0.060  0.440  0.268  1.0
  O  O19  1  0.571  0.908  0.247  1.0
  O  O20  1  0.937  0.564  0.734  1.0
  O  O21  1  0.424  0.083  0.760  1.0
  O  O22  1  0.223  0.494  0.429  1.0
  O  O23  1  0.490  0.790  0.088  1.0
  O  O24  1  0.775  0.506  0.574  1.0
  O  O25  1  0.511  0.206  0.907  1.0
  O  O26  1  0.284  0.641  0.061  1.0
  O  O27  1  0.370  0.707  0.439  1.0
  O  O28  1  0.716  0.364  0.931  1.0
  O  O29  1  0.630  0.284  0.562  1.0
  O  O30  1  0.929  0.227  0.264  1.0
  O  O31  1  0.789  0.054  0.241  1.0
  O  O32  1  0.080  0.771  0.731  1.0
  O  O33  1  0.219  0.946  0.758  1.0
  P  P34  1  0.978  0.039  0.248  1.0
  P  P35  1  0.043  0.957  0.743  1.0
  P  P36  1  0.531  0.745  0.259  1.0
  P  P37  1  0.464  0.248  0.735  1.0
  Si  Si38  1  0.239  0.469  0.249  1.0
  Si  Si39  1  0.752  0.556  0.743  1.0
[/CIF]
.