The crystal structure described by SiO2 crystallizes in the orthorhombic Fddd space group. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted corner-sharing SiO4 trigonal pyramids. There are four inequivalent O sites. In the first O site, O(2) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(3) is bonded in a bent 150 degrees 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   12.649
_cell_length_b   11.895
_cell_length_c   5.850
_cell_angle_alpha   83.522
_cell_angle_beta   69.124
_cell_angle_gamma   27.354
_symmetry_Int_Tables_number   1
_cell_volume   332.646
_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  0.998  0.370  0.201  1.0
  Si  Si1  1  0.370  0.998  0.431  1.0
  Si  Si2  1  0.252  0.880  0.049  1.0
  Si  Si3  1  0.049  0.819  0.252  1.0
  Si  Si4  1  0.880  0.252  0.819  1.0
  Si  Si5  1  0.201  0.431  0.998  1.0
  Si  Si6  1  0.819  0.049  0.880  1.0
  Si  Si7  1  0.431  0.201  0.370  1.0
  O  O8  1  0.032  0.468  0.032  1.0
  O  O9  1  0.125  0.125  0.125  1.0
  O  O10  1  0.298  0.298  0.202  1.0
  O  O11  1  0.910  0.910  0.590  1.0
  O  O12  1  0.218  0.782  0.218  1.0
  O  O13  1  0.952  0.952  0.048  1.0
  O  O14  1  0.202  0.202  0.298  1.0
  O  O15  1  0.468  0.032  0.468  1.0
  O  O16  1  0.782  0.218  0.782  1.0
  O  O17  1  0.340  0.340  0.660  1.0
  O  O18  1  0.048  0.048  0.952  1.0
  O  O19  1  0.590  0.590  0.910  1.0
  O  O20  1  0.125  0.125  0.625  1.0
  O  O21  1  0.660  0.660  0.340  1.0
  O  O22  1  0.125  0.625  0.125  1.0
  O  O23  1  0.625  0.125  0.125  1.0
[/CIF]
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The crystal structure described by SiO2 crystallizes in the orthorhombic Fddd space group. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted corner-sharing SiO4 trigonal pyramids. There are four inequivalent O sites. In the first O site, O(2) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(3) is bonded in a bent 150 degrees 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   12.649
_cell_length_b   11.895
_cell_length_c   5.850
_cell_angle_alpha   83.522
_cell_angle_beta   69.124
_cell_angle_gamma   27.354
_symmetry_Int_Tables_number   1
_cell_volume   332.646
_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  0.998  0.370  0.201  1.0
  Si  Si1  1  0.370  0.998  0.431  1.0
  Si  Si2  1  0.252  0.880  0.049  1.0
  Si  Si3  1  0.049  0.819  0.252  1.0
  Si  Si4  1  0.880  0.252  0.819  1.0
  Si  Si5  1  0.201  0.431  0.998  1.0
  Si  Si6  1  0.819  0.049  0.880  1.0
  Si  Si7  1  0.431  0.201  0.370  1.0
  O  O8  1  0.032  0.468  0.032  1.0
  O  O9  1  0.125  0.125  0.125  1.0
  O  O10  1  0.298  0.298  0.202  1.0
  O  O11  1  0.910  0.910  0.590  1.0
  O  O12  1  0.218  0.782  0.218  1.0
  O  O13  1  0.952  0.952  0.048  1.0
  O  O14  1  0.202  0.202  0.298  1.0
  O  O15  1  0.468  0.032  0.468  1.0
  O  O16  1  0.782  0.218  0.782  1.0
  O  O17  1  0.340  0.340  0.660  1.0
  O  O18  1  0.048  0.048  0.952  1.0
  O  O19  1  0.590  0.590  0.910  1.0
  O  O20  1  0.125  0.125  0.625  1.0
  O  O21  1  0.660  0.660  0.340  1.0
  O  O22  1  0.125  0.625  0.125  1.0
  O  O23  1  0.625  0.125  0.125  1.0
[/CIF]
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