The material described by Na7Al3O8 crystallizes in the triclinic P-1 space group. There are seven inequivalent Na sites. In the first Na site, Na(1) is bonded in a 1-coordinate geometry to one O(4), one O(6), one O(7), and one O(8) atom. In the second Na site, Na(2) is bonded in a distorted L-shaped geometry to one O(5) and one O(7) atom. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to one O(3), one O(5), one O(6), and one O(8) atom. In the fourth Na site, Na(4) is bonded in a distorted single-bond geometry to one O(5), one O(8), and two equivalent O(7) atoms. In the fifth Na site, Na(5) is bonded in a single-bond geometry to one O(2), one O(7), and one O(8) atom. In the sixth Na site, Na(6) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(4) atom. In the seventh Na site, Na(7) is bonded in a distorted single-bond geometry to one O(2), one O(6), and one O(8) atom. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 4-coordinate geometry to one O(1), one O(4), one O(6), and one O(8) atom. In the second Al site, Al(2) is bonded in a 3-coordinate geometry to one O(3), one O(5), and one O(7) atom. In the third Al site, Al(3) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(6) atom. There are eight inequivalent O sites. In the first O site, O(8) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), one Na(5), one Na(7), and one Al(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Na(6), one Al(1), and one Al(3) atom. In the third O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Na(5), one Na(6), one Na(7), and one Al(3) atom. In the fourth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Na(3), one Al(2), and one Al(3) atom. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Na(6), and one Al(1) atom. In the sixth O site, O(5) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Na(4), and one Al(2) atom. In the seventh O site, O(6) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(7), one Al(1), and one Al(3) atom. In the eighth O site, O(7) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(5), two equivalent Na(4), and one Al(2) atom. is represented by the CIF card [CIF]
data_Na7Al3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.919
_cell_length_b   8.036
_cell_length_c   11.409
_cell_angle_alpha   110.542
_cell_angle_beta   89.774
_cell_angle_gamma   108.912
_symmetry_Int_Tables_number   1
_cell_volume   477.031
_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
  Na  Na0  1  0.849  0.767  0.333  1.0
  Na  Na1  1  0.723  0.931  0.552  1.0
  Na  Na2  1  0.447  0.931  0.762  1.0
  Na  Na3  1  0.628  0.357  0.556  1.0
  Na  Na4  1  0.372  0.643  0.444  1.0
  Na  Na5  1  0.471  0.437  0.271  1.0
  Na  Na6  1  0.277  0.069  0.448  1.0
  Na  Na7  1  0.151  0.233  0.667  1.0
  Na  Na8  1  0.255  0.547  0.944  1.0
  Na  Na9  1  0.659  0.851  0.052  1.0
  Na  Na10  1  0.745  0.453  0.056  1.0
  Na  Na11  1  0.529  0.563  0.729  1.0
  Na  Na12  1  0.553  0.069  0.238  1.0
  Na  Na13  1  0.341  0.149  0.948  1.0
  Al  Al14  1  0.835  0.253  0.841  1.0
  Al  Al15  1  0.165  0.747  0.159  1.0
  Al  Al16  1  0.959  0.321  0.354  1.0
  Al  Al17  1  0.041  0.679  0.646  1.0
  Al  Al18  1  0.069  0.164  0.136  1.0
  Al  Al19  1  0.931  0.836  0.864  1.0
  O  O20  1  0.154  0.772  0.995  1.0
  O  O21  1  0.639  0.699  0.896  1.0
  O  O22  1  0.021  0.829  0.728  1.0
  O  O23  1  0.950  0.544  0.240  1.0
  O  O24  1  0.680  0.215  0.418  1.0
  O  O25  1  0.068  0.931  0.166  1.0
  O  O26  1  0.221  0.336  0.464  1.0
  O  O27  1  0.050  0.456  0.760  1.0
  O  O28  1  0.361  0.301  0.104  1.0
  O  O29  1  0.979  0.171  0.272  1.0
  O  O30  1  0.932  0.069  0.834  1.0
  O  O31  1  0.779  0.664  0.536  1.0
  O  O32  1  0.464  0.759  0.231  1.0
  O  O33  1  0.846  0.228  0.005  1.0
  O  O34  1  0.536  0.241  0.769  1.0
  O  O35  1  0.320  0.785  0.582  1.0
[/CIF]
.
The material described by Na7Al3O8 crystallizes in the triclinic P-1 space group. There are seven inequivalent Na sites. In the first Na site, Na(1) is bonded in a 1-coordinate geometry to one O(4), one O(6), one O(7), and one O(8) atom. In the second Na site, Na(2) is bonded in a distorted L-shaped geometry to one O(5) and one O(7) atom. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to one O(3), one O(5), one O(6), and one O(8) atom. In the fourth Na site, Na(4) is bonded in a distorted single-bond geometry to one O(5), one O(8), and two equivalent O(7) atoms. In the fifth Na site, Na(5) is bonded in a single-bond geometry to one O(2), one O(7), and one O(8) atom. In the sixth Na site, Na(6) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(4) atom. In the seventh Na site, Na(7) is bonded in a distorted single-bond geometry to one O(2), one O(6), and one O(8) atom. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a 4-coordinate geometry to one O(1), one O(4), one O(6), and one O(8) atom. In the second Al site, Al(2) is bonded in a 3-coordinate geometry to one O(3), one O(5), and one O(7) atom. In the third Al site, Al(3) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(6) atom. There are eight inequivalent O sites. In the first O site, O(8) is bonded in a 6-coordinate geometry to one Na(1), one Na(3), one Na(4), one Na(5), one Na(7), and one Al(1) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Na(6), one Al(1), and one Al(3) atom. In the third O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Na(5), one Na(6), one Na(7), and one Al(3) atom. In the fourth O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Na(3), one Al(2), and one Al(3) atom. In the fifth O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Na(6), and one Al(1) atom. In the sixth O site, O(5) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Na(4), and one Al(2) atom. In the seventh O site, O(6) is bonded in a 5-coordinate geometry to one Na(1), one Na(3), one Na(7), one Al(1), and one Al(3) atom. In the eighth O site, O(7) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), one Na(5), two equivalent Na(4), and one Al(2) atom. is represented by the CIF card [CIF]
data_Na7Al3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.919
_cell_length_b   8.036
_cell_length_c   11.409
_cell_angle_alpha   110.542
_cell_angle_beta   89.774
_cell_angle_gamma   108.912
_symmetry_Int_Tables_number   1
_cell_volume   477.031
_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
  Na  Na0  1  0.849  0.767  0.333  1.0
  Na  Na1  1  0.723  0.931  0.552  1.0
  Na  Na2  1  0.447  0.931  0.762  1.0
  Na  Na3  1  0.628  0.357  0.556  1.0
  Na  Na4  1  0.372  0.643  0.444  1.0
  Na  Na5  1  0.471  0.437  0.271  1.0
  Na  Na6  1  0.277  0.069  0.448  1.0
  Na  Na7  1  0.151  0.233  0.667  1.0
  Na  Na8  1  0.255  0.547  0.944  1.0
  Na  Na9  1  0.659  0.851  0.052  1.0
  Na  Na10  1  0.745  0.453  0.056  1.0
  Na  Na11  1  0.529  0.563  0.729  1.0
  Na  Na12  1  0.553  0.069  0.238  1.0
  Na  Na13  1  0.341  0.149  0.948  1.0
  Al  Al14  1  0.835  0.253  0.841  1.0
  Al  Al15  1  0.165  0.747  0.159  1.0
  Al  Al16  1  0.959  0.321  0.354  1.0
  Al  Al17  1  0.041  0.679  0.646  1.0
  Al  Al18  1  0.069  0.164  0.136  1.0
  Al  Al19  1  0.931  0.836  0.864  1.0
  O  O20  1  0.154  0.772  0.995  1.0
  O  O21  1  0.639  0.699  0.896  1.0
  O  O22  1  0.021  0.829  0.728  1.0
  O  O23  1  0.950  0.544  0.240  1.0
  O  O24  1  0.680  0.215  0.418  1.0
  O  O25  1  0.068  0.931  0.166  1.0
  O  O26  1  0.221  0.336  0.464  1.0
  O  O27  1  0.050  0.456  0.760  1.0
  O  O28  1  0.361  0.301  0.104  1.0
  O  O29  1  0.979  0.171  0.272  1.0
  O  O30  1  0.932  0.069  0.834  1.0
  O  O31  1  0.779  0.664  0.536  1.0
  O  O32  1  0.464  0.759  0.231  1.0
  O  O33  1  0.846  0.228  0.005  1.0
  O  O34  1  0.536  0.241  0.769  1.0
  O  O35  1  0.320  0.785  0.582  1.0
[/CIF]
.