The structure described by SiO2 crystallizes in the tetragonal I4_122 space group. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) 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   12.071
_cell_length_b   12.071
_cell_length_c   12.071
_cell_angle_alpha   152.129
_cell_angle_beta   152.129
_cell_angle_gamma   39.825
_symmetry_Int_Tables_number   1
_cell_volume   383.662
_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  0.060  0.685  0.122  1.0
  Si  Si1  1  0.187  0.565  0.875  1.0
  Si  Si2  1  0.435  0.813  0.125  1.0
  Si  Si3  1  0.315  0.940  0.878  1.0
  Si  Si4  1  0.690  0.312  0.125  1.0
  Si  Si5  1  0.563  0.938  0.878  1.0
  Si  Si6  1  0.688  0.310  0.875  1.0
  Si  Si7  1  0.062  0.437  0.122  1.0
  O  O8  1  0.815  0.815  0.000  1.0
  O  O9  1  0.774  0.226  0.000  1.0
  O  O10  1  0.610  0.125  0.985  1.0
  O  O11  1  0.875  0.390  0.015  1.0
  O  O12  1  0.308  0.808  0.500  1.0
  O  O13  1  0.976  0.476  0.953  1.0
  O  O14  1  0.140  0.625  0.015  1.0
  O  O15  1  0.935  0.435  0.500  1.0
  O  O16  1  0.192  0.692  0.500  1.0
  O  O17  1  0.226  0.774  0.000  1.0
  O  O18  1  0.185  0.185  0.000  1.0
  O  O19  1  0.565  0.065  0.500  1.0
  O  O20  1  0.442  0.442  0.000  1.0
  O  O21  1  0.524  0.024  0.047  1.0
  O  O22  1  0.558  0.558  0.000  1.0
  O  O23  1  0.375  0.860  0.985  1.0
[/CIF]
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The structure described by SiO2 crystallizes in the tetragonal I4_122 space group. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) 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   12.071
_cell_length_b   12.071
_cell_length_c   12.071
_cell_angle_alpha   152.129
_cell_angle_beta   152.129
_cell_angle_gamma   39.825
_symmetry_Int_Tables_number   1
_cell_volume   383.662
_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  0.060  0.685  0.122  1.0
  Si  Si1  1  0.187  0.565  0.875  1.0
  Si  Si2  1  0.435  0.813  0.125  1.0
  Si  Si3  1  0.315  0.940  0.878  1.0
  Si  Si4  1  0.690  0.312  0.125  1.0
  Si  Si5  1  0.563  0.938  0.878  1.0
  Si  Si6  1  0.688  0.310  0.875  1.0
  Si  Si7  1  0.062  0.437  0.122  1.0
  O  O8  1  0.815  0.815  0.000  1.0
  O  O9  1  0.774  0.226  0.000  1.0
  O  O10  1  0.610  0.125  0.985  1.0
  O  O11  1  0.875  0.390  0.015  1.0
  O  O12  1  0.308  0.808  0.500  1.0
  O  O13  1  0.976  0.476  0.953  1.0
  O  O14  1  0.140  0.625  0.015  1.0
  O  O15  1  0.935  0.435  0.500  1.0
  O  O16  1  0.192  0.692  0.500  1.0
  O  O17  1  0.226  0.774  0.000  1.0
  O  O18  1  0.185  0.185  0.000  1.0
  O  O19  1  0.565  0.065  0.500  1.0
  O  O20  1  0.442  0.442  0.000  1.0
  O  O21  1  0.524  0.024  0.047  1.0
  O  O22  1  0.558  0.558  0.000  1.0
  O  O23  1  0.375  0.860  0.985  1.0
[/CIF]
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