The crystal structure described by SiO2 is High (Orthorhombic) Tridymite-like structured and crystallizes in the tetragonal I-4c2 space group. Si(1) is bonded to two equivalent O(1) and two equivalent O(2,3) atoms to form corner-sharing SiO4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2,3) is bonded in a linear geometry to two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.333
_cell_length_b   8.333
_cell_length_c   8.333
_cell_angle_alpha   105.239
_cell_angle_beta   105.239
_cell_angle_gamma   118.315
_symmetry_Int_Tables_number   1
_cell_volume   437.404
_cell_formula_units_Z   8
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
  Si  Si0  1  0.918  0.208  0.000  1.0
  Si  Si1  1  0.707  0.708  0.290  1.0
  Si  Si2  1  0.292  0.582  1.000  1.0
  Si  Si3  1  0.792  0.793  0.710  1.0
  Si  Si4  1  0.583  0.293  0.000  1.0
  Si  Si5  1  0.207  0.917  1.000  1.0
  Si  Si6  1  0.418  0.417  0.710  1.0
  Si  Si7  1  0.083  0.082  0.290  1.0
  O  O8  1  0.501  0.315  0.815  1.0
  O  O9  1  1.000  0.815  0.815  1.0
  O  O10  1  0.606  0.606  0.712  1.0
  O  O11  1  0.751  0.251  0.001  1.0
  O  O12  1  0.500  0.685  0.185  1.0
  O  O13  1  0.251  0.249  0.500  1.0
  O  O14  1  0.894  0.894  0.288  1.0
  O  O15  1  0.685  0.500  0.185  1.0
  O  O16  1  0.749  0.751  0.500  1.0
  O  O17  1  0.815  0.000  0.815  1.0
  O  O18  1  0.185  0.999  0.185  1.0
  O  O19  1  0.394  0.106  0.000  1.0
  O  O20  1  0.001  0.185  0.185  1.0
  O  O21  1  0.315  0.499  0.815  1.0
  O  O22  1  0.106  0.394  0.000  1.0
  O  O23  1  0.249  0.749  0.999  1.0
[/CIF]
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The crystal structure described by SiO2 is High (Orthorhombic) Tridymite-like structured and crystallizes in the tetragonal I-4c2 space group. Si(1) is bonded to two equivalent O(1) and two equivalent O(2,3) atoms to form corner-sharing SiO4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(2,3) is bonded in a linear geometry to two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.333
_cell_length_b   8.333
_cell_length_c   8.333
_cell_angle_alpha   105.239
_cell_angle_beta   105.239
_cell_angle_gamma   118.315
_symmetry_Int_Tables_number   1
_cell_volume   437.404
_cell_formula_units_Z   8
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
  Si  Si0  1  0.918  0.208  0.000  1.0
  Si  Si1  1  0.707  0.708  0.290  1.0
  Si  Si2  1  0.292  0.582  1.000  1.0
  Si  Si3  1  0.792  0.793  0.710  1.0
  Si  Si4  1  0.583  0.293  0.000  1.0
  Si  Si5  1  0.207  0.917  1.000  1.0
  Si  Si6  1  0.418  0.417  0.710  1.0
  Si  Si7  1  0.083  0.082  0.290  1.0
  O  O8  1  0.501  0.315  0.815  1.0
  O  O9  1  1.000  0.815  0.815  1.0
  O  O10  1  0.606  0.606  0.712  1.0
  O  O11  1  0.751  0.251  0.001  1.0
  O  O12  1  0.500  0.685  0.185  1.0
  O  O13  1  0.251  0.249  0.500  1.0
  O  O14  1  0.894  0.894  0.288  1.0
  O  O15  1  0.685  0.500  0.185  1.0
  O  O16  1  0.749  0.751  0.500  1.0
  O  O17  1  0.815  0.000  0.815  1.0
  O  O18  1  0.185  0.999  0.185  1.0
  O  O19  1  0.394  0.106  0.000  1.0
  O  O20  1  0.001  0.185  0.185  1.0
  O  O21  1  0.315  0.499  0.815  1.0
  O  O22  1  0.106  0.394  0.000  1.0
  O  O23  1  0.249  0.749  0.999  1.0
[/CIF]
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