The material structure described by NaAlSi3O8 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(7), and two equivalent O(1) atoms. Al(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Na(1), one Si(2), and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Al(1) and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. is represented by the CIF card [CIF]
data_NaAlSi3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.706
_cell_length_b   7.421
_cell_length_c   7.171
_cell_angle_alpha   79.519
_cell_angle_beta   107.499
_cell_angle_gamma   64.704
_symmetry_Int_Tables_number   1
_cell_volume   329.877
_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  0.750  0.274  0.855  1.0
  Na  Na1  1  0.250  0.726  0.145  1.0
  Al  Al2  1  0.825  0.842  0.793  1.0
  Al  Al3  1  0.175  0.158  0.207  1.0
  Si  Si4  1  0.174  0.181  0.763  1.0
  Si  Si5  1  0.826  0.819  0.237  1.0
  Si  Si6  1  0.202  0.579  0.688  1.0
  Si  Si7  1  0.798  0.421  0.312  1.0
  Si  Si8  1  0.441  0.795  0.641  1.0
  Si  Si9  1  0.559  0.205  0.359  1.0
  O  O10  1  0.867  0.877  0.034  1.0
  O  O11  1  0.133  0.123  0.966  1.0
  O  O12  1  0.418  0.587  0.722  1.0
  O  O13  1  0.582  0.413  0.278  1.0
  O  O14  1  0.082  0.705  0.811  1.0
  O  O15  1  0.918  0.295  0.189  1.0
  O  O16  1  0.328  0.966  0.740  1.0
  O  O17  1  0.672  0.034  0.260  1.0
  O  O18  1  0.690  0.708  0.732  1.0
  O  O19  1  0.310  0.292  0.268  1.0
  O  O20  1  0.284  0.326  0.776  1.0
  O  O21  1  0.716  0.674  0.224  1.0
  O  O22  1  0.680  0.103  0.611  1.0
  O  O23  1  0.320  0.897  0.389  1.0
  O  O24  1  0.945  0.318  0.562  1.0
  O  O25  1  0.055  0.682  0.438  1.0
[/CIF]
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The material structure described by NaAlSi3O8 crystallizes in the triclinic P-1 space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(7), and two equivalent O(1) atoms. Al(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Na(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Na(1), one Si(2), and one Si(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Al(1) and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(1), one Al(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. is represented by the CIF card [CIF]
data_NaAlSi3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.706
_cell_length_b   7.421
_cell_length_c   7.171
_cell_angle_alpha   79.519
_cell_angle_beta   107.499
_cell_angle_gamma   64.704
_symmetry_Int_Tables_number   1
_cell_volume   329.877
_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  0.750  0.274  0.855  1.0
  Na  Na1  1  0.250  0.726  0.145  1.0
  Al  Al2  1  0.825  0.842  0.793  1.0
  Al  Al3  1  0.175  0.158  0.207  1.0
  Si  Si4  1  0.174  0.181  0.763  1.0
  Si  Si5  1  0.826  0.819  0.237  1.0
  Si  Si6  1  0.202  0.579  0.688  1.0
  Si  Si7  1  0.798  0.421  0.312  1.0
  Si  Si8  1  0.441  0.795  0.641  1.0
  Si  Si9  1  0.559  0.205  0.359  1.0
  O  O10  1  0.867  0.877  0.034  1.0
  O  O11  1  0.133  0.123  0.966  1.0
  O  O12  1  0.418  0.587  0.722  1.0
  O  O13  1  0.582  0.413  0.278  1.0
  O  O14  1  0.082  0.705  0.811  1.0
  O  O15  1  0.918  0.295  0.189  1.0
  O  O16  1  0.328  0.966  0.740  1.0
  O  O17  1  0.672  0.034  0.260  1.0
  O  O18  1  0.690  0.708  0.732  1.0
  O  O19  1  0.310  0.292  0.268  1.0
  O  O20  1  0.284  0.326  0.776  1.0
  O  O21  1  0.716  0.674  0.224  1.0
  O  O22  1  0.680  0.103  0.611  1.0
  O  O23  1  0.320  0.897  0.389  1.0
  O  O24  1  0.945  0.318  0.562  1.0
  O  O25  1  0.055  0.682  0.438  1.0
[/CIF]
.