The crystal structure described by SiO2 crystallizes in the tetragonal P4/nbm space group. Si(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. There are three 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(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the third O site, O(2) 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   9.716
_cell_length_b   9.716
_cell_length_c   4.238
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   400.044
_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  0.851  0.649  0.170  1.0
  Si  Si1  1  0.649  0.851  0.830  1.0
  Si  Si2  1  0.149  0.649  0.830  1.0
  Si  Si3  1  0.851  0.351  0.830  1.0
  Si  Si4  1  0.149  0.351  0.170  1.0
  Si  Si5  1  0.351  0.149  0.830  1.0
  Si  Si6  1  0.649  0.149  0.170  1.0
  Si  Si7  1  0.351  0.851  0.170  1.0
  O  O8  1  0.500  0.811  0.000  1.0
  O  O9  1  0.250  0.250  0.000  1.0
  O  O10  1  0.689  0.000  0.000  1.0
  O  O11  1  0.811  0.500  0.000  1.0
  O  O12  1  0.750  0.750  0.500  1.0
  O  O13  1  0.189  0.500  0.000  1.0
  O  O14  1  0.250  0.750  0.500  1.0
  O  O15  1  0.500  0.189  0.000  1.0
  O  O16  1  0.250  0.250  0.500  1.0
  O  O17  1  0.000  0.311  0.000  1.0
  O  O18  1  0.750  0.250  0.500  1.0
  O  O19  1  0.311  0.000  0.000  1.0
  O  O20  1  0.250  0.750  0.000  1.0
  O  O21  1  0.000  0.689  0.000  1.0
  O  O22  1  0.750  0.750  0.000  1.0
  O  O23  1  0.750  0.250  0.000  1.0
[/CIF]
.
The crystal structure described by SiO2 crystallizes in the tetragonal P4/nbm space group. Si(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. There are three 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(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the third O site, O(2) 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   9.716
_cell_length_b   9.716
_cell_length_c   4.238
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   400.044
_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  0.851  0.649  0.170  1.0
  Si  Si1  1  0.649  0.851  0.830  1.0
  Si  Si2  1  0.149  0.649  0.830  1.0
  Si  Si3  1  0.851  0.351  0.830  1.0
  Si  Si4  1  0.149  0.351  0.170  1.0
  Si  Si5  1  0.351  0.149  0.830  1.0
  Si  Si6  1  0.649  0.149  0.170  1.0
  Si  Si7  1  0.351  0.851  0.170  1.0
  O  O8  1  0.500  0.811  0.000  1.0
  O  O9  1  0.250  0.250  0.000  1.0
  O  O10  1  0.689  0.000  0.000  1.0
  O  O11  1  0.811  0.500  0.000  1.0
  O  O12  1  0.750  0.750  0.500  1.0
  O  O13  1  0.189  0.500  0.000  1.0
  O  O14  1  0.250  0.750  0.500  1.0
  O  O15  1  0.500  0.189  0.000  1.0
  O  O16  1  0.250  0.250  0.500  1.0
  O  O17  1  0.000  0.311  0.000  1.0
  O  O18  1  0.750  0.250  0.500  1.0
  O  O19  1  0.311  0.000  0.000  1.0
  O  O20  1  0.250  0.750  0.000  1.0
  O  O21  1  0.000  0.689  0.000  1.0
  O  O22  1  0.750  0.750  0.000  1.0
  O  O23  1  0.750  0.250  0.000  1.0
[/CIF]
.