The structure described by SiO2 crystallizes in the trigonal P-31m 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 150 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a water-like geometry to two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.741
_cell_length_b   11.741
_cell_length_c   4.447
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   530.921
_cell_formula_units_Z   12
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  0.850  0.539  0.783  1.0
  Si  Si1  1  0.689  0.539  0.217  1.0
  Si  Si2  1  0.311  0.850  0.217  1.0
  Si  Si3  1  0.689  0.150  0.783  1.0
  Si  Si4  1  0.150  0.689  0.783  1.0
  Si  Si5  1  0.539  0.689  0.217  1.0
  Si  Si6  1  0.461  0.150  0.217  1.0
  Si  Si7  1  0.311  0.461  0.783  1.0
  Si  Si8  1  0.150  0.461  0.217  1.0
  Si  Si9  1  0.539  0.850  0.783  1.0
  Si  Si10  1  0.850  0.311  0.217  1.0
  Si  Si11  1  0.461  0.311  0.783  1.0
  O  O12  1  0.581  0.419  0.000  1.0
  O  O13  1  0.419  0.581  0.000  1.0
  O  O14  1  0.253  0.747  0.500  1.0
  O  O15  1  0.000  0.378  0.346  1.0
  O  O16  1  0.622  0.000  0.654  1.0
  O  O17  1  0.837  0.419  0.000  1.0
  O  O18  1  0.370  0.185  0.000  1.0
  O  O19  1  0.747  0.253  0.500  1.0
  O  O20  1  0.581  0.163  0.000  1.0
  O  O21  1  0.630  0.815  0.000  1.0
  O  O22  1  0.622  0.622  0.346  1.0
  O  O23  1  0.495  0.747  0.500  1.0
  O  O24  1  0.815  0.630  0.000  1.0
  O  O25  1  0.378  0.378  0.654  1.0
  O  O26  1  0.747  0.495  0.500  1.0
  O  O27  1  0.419  0.837  0.000  1.0
  O  O28  1  0.000  0.622  0.654  1.0
  O  O29  1  0.378  0.000  0.346  1.0
  O  O30  1  0.253  0.505  0.500  1.0
  O  O31  1  0.185  0.370  0.000  1.0
  O  O32  1  0.815  0.185  0.000  1.0
  O  O33  1  0.163  0.581  0.000  1.0
  O  O34  1  0.505  0.253  0.500  1.0
  O  O35  1  0.185  0.815  0.000  1.0
[/CIF]
.
The structure described by SiO2 crystallizes in the trigonal P-31m 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 150 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a water-like geometry to two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.741
_cell_length_b   11.741
_cell_length_c   4.447
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   530.921
_cell_formula_units_Z   12
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  0.850  0.539  0.783  1.0
  Si  Si1  1  0.689  0.539  0.217  1.0
  Si  Si2  1  0.311  0.850  0.217  1.0
  Si  Si3  1  0.689  0.150  0.783  1.0
  Si  Si4  1  0.150  0.689  0.783  1.0
  Si  Si5  1  0.539  0.689  0.217  1.0
  Si  Si6  1  0.461  0.150  0.217  1.0
  Si  Si7  1  0.311  0.461  0.783  1.0
  Si  Si8  1  0.150  0.461  0.217  1.0
  Si  Si9  1  0.539  0.850  0.783  1.0
  Si  Si10  1  0.850  0.311  0.217  1.0
  Si  Si11  1  0.461  0.311  0.783  1.0
  O  O12  1  0.581  0.419  0.000  1.0
  O  O13  1  0.419  0.581  0.000  1.0
  O  O14  1  0.253  0.747  0.500  1.0
  O  O15  1  0.000  0.378  0.346  1.0
  O  O16  1  0.622  0.000  0.654  1.0
  O  O17  1  0.837  0.419  0.000  1.0
  O  O18  1  0.370  0.185  0.000  1.0
  O  O19  1  0.747  0.253  0.500  1.0
  O  O20  1  0.581  0.163  0.000  1.0
  O  O21  1  0.630  0.815  0.000  1.0
  O  O22  1  0.622  0.622  0.346  1.0
  O  O23  1  0.495  0.747  0.500  1.0
  O  O24  1  0.815  0.630  0.000  1.0
  O  O25  1  0.378  0.378  0.654  1.0
  O  O26  1  0.747  0.495  0.500  1.0
  O  O27  1  0.419  0.837  0.000  1.0
  O  O28  1  0.000  0.622  0.654  1.0
  O  O29  1  0.378  0.000  0.346  1.0
  O  O30  1  0.253  0.505  0.500  1.0
  O  O31  1  0.185  0.370  0.000  1.0
  O  O32  1  0.815  0.185  0.000  1.0
  O  O33  1  0.163  0.581  0.000  1.0
  O  O34  1  0.505  0.253  0.500  1.0
  O  O35  1  0.185  0.815  0.000  1.0
[/CIF]
.