The material described by Na2NbAlSi2SO12 crystallizes in the monoclinic Cc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(4), one O(6), one O(7), one O(8), and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom. Nb(1) is bonded to one O(10), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent S(1)O4 tetrahedra. Al(1) is bonded to one O(1), one O(2), one O(3), one O(7), one O(8), and one O(9) atom to form distorted AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent S(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(2), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-37°. In the second Si site, Si(2) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-33°. S(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form SO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-36°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one S(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Al(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Nb(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Nb(1), and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal pyramidal geometry to one Na(1), one Na(2), one Al(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Al(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Al(1), and one S(1) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Nb(1), and one S(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(2), one Nb(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Nb(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_Na2NbAlSi2SO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.840
_cell_length_b   8.840
_cell_length_c   8.960
_cell_angle_alpha   91.478
_cell_angle_beta   118.115
_cell_angle_gamma   119.749
_symmetry_Int_Tables_number   1
_cell_volume   504.453
_cell_formula_units_Z   2
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  0.308  0.677  0.937  1.0
  Al  Al1  1  0.261  0.130  0.437  1.0
  Na  Na2  1  0.876  0.762  0.250  1.0
  Na  Na3  1  0.489  0.874  0.750  1.0
  Na  Na4  1  0.017  0.491  0.517  1.0
  Na  Na5  1  0.026  0.000  0.017  1.0
  Nb  Nb6  1  0.710  0.359  0.066  1.0
  Nb  Nb7  1  0.708  0.856  0.566  1.0
  O  O8  1  0.363  0.484  0.086  1.0
  O  O9  1  0.588  0.858  0.066  1.0
  O  O10  1  0.226  0.715  0.075  1.0
  O  O11  1  0.208  0.978  0.566  1.0
  O  O12  1  0.602  0.223  0.586  1.0
  O  O13  1  0.360  0.349  0.575  1.0
  O  O14  1  0.644  0.510  0.930  1.0
  O  O15  1  0.425  0.142  0.919  1.0
  O  O16  1  0.787  0.280  0.911  1.0
  O  O17  1  0.777  0.994  0.419  1.0
  O  O18  1  0.420  0.786  0.430  1.0
  O  O19  1  0.631  0.623  0.411  1.0
  O  O20  1  0.330  0.559  0.774  1.0
  O  O21  1  0.204  0.774  0.768  1.0
  O  O22  1  0.982  0.415  0.770  1.0
  O  O23  1  0.994  0.064  0.268  1.0
  O  O24  1  0.215  0.944  0.274  1.0
  O  O25  1  0.356  0.288  0.270  1.0
  O  O26  1  0.650  0.445  0.238  1.0
  O  O27  1  0.798  0.230  0.232  1.0
  O  O28  1  0.005  0.585  0.226  1.0
  O  O29  1  0.003  0.934  0.732  1.0
  O  O30  1  0.794  0.088  0.738  1.0
  O  O31  1  0.641  0.722  0.726  1.0
  S  S32  1  0.485  0.454  0.245  1.0
  S  S33  1  0.791  0.260  0.745  1.0
  Si  Si34  1  0.788  0.039  0.243  1.0
  Si  Si35  1  0.220  0.764  0.245  1.0
  Si  Si36  1  0.204  0.955  0.743  1.0
  Si  Si37  1  0.481  0.525  0.745  1.0
[/CIF]
.
The material described by Na2NbAlSi2SO12 crystallizes in the monoclinic Cc space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(4), one O(6), one O(7), one O(8), and two equivalent O(2) atoms. In the second Na site, Na(2) is bonded in a distorted hexagonal planar geometry to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom. Nb(1) is bonded to one O(10), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent S(1)O4 tetrahedra. Al(1) is bonded to one O(1), one O(2), one O(3), one O(7), one O(8), and one O(9) atom to form distorted AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent S(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(2), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 20-37°. In the second Si site, Si(2) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 17-33°. S(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form SO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-36°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one S(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Al(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Nb(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Nb(1) and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Nb(1), and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal pyramidal geometry to one Na(1), one Na(2), one Al(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Al(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Al(1), and one S(1) atom. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Nb(1), and one S(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(2), one Nb(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Nb(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_Na2NbAlSi2SO12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.840
_cell_length_b   8.840
_cell_length_c   8.960
_cell_angle_alpha   91.478
_cell_angle_beta   118.115
_cell_angle_gamma   119.749
_symmetry_Int_Tables_number   1
_cell_volume   504.453
_cell_formula_units_Z   2
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  0.308  0.677  0.937  1.0
  Al  Al1  1  0.261  0.130  0.437  1.0
  Na  Na2  1  0.876  0.762  0.250  1.0
  Na  Na3  1  0.489  0.874  0.750  1.0
  Na  Na4  1  0.017  0.491  0.517  1.0
  Na  Na5  1  0.026  0.000  0.017  1.0
  Nb  Nb6  1  0.710  0.359  0.066  1.0
  Nb  Nb7  1  0.708  0.856  0.566  1.0
  O  O8  1  0.363  0.484  0.086  1.0
  O  O9  1  0.588  0.858  0.066  1.0
  O  O10  1  0.226  0.715  0.075  1.0
  O  O11  1  0.208  0.978  0.566  1.0
  O  O12  1  0.602  0.223  0.586  1.0
  O  O13  1  0.360  0.349  0.575  1.0
  O  O14  1  0.644  0.510  0.930  1.0
  O  O15  1  0.425  0.142  0.919  1.0
  O  O16  1  0.787  0.280  0.911  1.0
  O  O17  1  0.777  0.994  0.419  1.0
  O  O18  1  0.420  0.786  0.430  1.0
  O  O19  1  0.631  0.623  0.411  1.0
  O  O20  1  0.330  0.559  0.774  1.0
  O  O21  1  0.204  0.774  0.768  1.0
  O  O22  1  0.982  0.415  0.770  1.0
  O  O23  1  0.994  0.064  0.268  1.0
  O  O24  1  0.215  0.944  0.274  1.0
  O  O25  1  0.356  0.288  0.270  1.0
  O  O26  1  0.650  0.445  0.238  1.0
  O  O27  1  0.798  0.230  0.232  1.0
  O  O28  1  0.005  0.585  0.226  1.0
  O  O29  1  0.003  0.934  0.732  1.0
  O  O30  1  0.794  0.088  0.738  1.0
  O  O31  1  0.641  0.722  0.726  1.0
  S  S32  1  0.485  0.454  0.245  1.0
  S  S33  1  0.791  0.260  0.745  1.0
  Si  Si34  1  0.788  0.039  0.243  1.0
  Si  Si35  1  0.220  0.764  0.245  1.0
  Si  Si36  1  0.204  0.955  0.743  1.0
  Si  Si37  1  0.481  0.525  0.745  1.0
[/CIF]
.