The structure described by SiO2 is High (Orthorhombic) Tridymite-like structured and crystallizes in the trigonal R-3m space group. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form corner-sharing SiO4 tetrahedra. There are three 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 linear 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. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.536
_cell_length_b   8.536
_cell_length_c   8.536
_cell_angle_alpha   116.188
_cell_angle_beta   116.188
_cell_angle_gamma   116.188
_symmetry_Int_Tables_number   1
_cell_volume   307.138
_cell_formula_units_Z   6
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  0.806  0.806  0.185  1.0
  Si  Si1  1  0.815  0.194  0.194  1.0
  Si  Si2  1  0.806  0.185  0.806  1.0
  Si  Si3  1  0.194  0.815  0.194  1.0
  Si  Si4  1  0.185  0.806  0.806  1.0
  Si  Si5  1  0.194  0.194  0.815  1.0
  O  O6  1  0.177  0.000  0.823  1.0
  O  O7  1  0.500  0.000  0.500  1.0
  O  O8  1  0.823  0.177  0.000  1.0
  O  O9  1  0.177  0.823  0.000  1.0
  O  O10  1  0.500  0.500  0.000  1.0
  O  O11  1  0.500  0.000  0.000  1.0
  O  O12  1  0.000  0.823  0.177  1.0
  O  O13  1  0.000  0.000  0.500  1.0
  O  O14  1  0.823  0.000  0.177  1.0
  O  O15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.000  0.177  0.823  1.0
  O  O17  1  0.000  0.500  0.000  1.0
[/CIF]
.
The structure described by SiO2 is High (Orthorhombic) Tridymite-like structured and crystallizes in the trigonal R-3m space group. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form corner-sharing SiO4 tetrahedra. There are three 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 linear 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. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.536
_cell_length_b   8.536
_cell_length_c   8.536
_cell_angle_alpha   116.188
_cell_angle_beta   116.188
_cell_angle_gamma   116.188
_symmetry_Int_Tables_number   1
_cell_volume   307.138
_cell_formula_units_Z   6
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  0.806  0.806  0.185  1.0
  Si  Si1  1  0.815  0.194  0.194  1.0
  Si  Si2  1  0.806  0.185  0.806  1.0
  Si  Si3  1  0.194  0.815  0.194  1.0
  Si  Si4  1  0.185  0.806  0.806  1.0
  Si  Si5  1  0.194  0.194  0.815  1.0
  O  O6  1  0.177  0.000  0.823  1.0
  O  O7  1  0.500  0.000  0.500  1.0
  O  O8  1  0.823  0.177  0.000  1.0
  O  O9  1  0.177  0.823  0.000  1.0
  O  O10  1  0.500  0.500  0.000  1.0
  O  O11  1  0.500  0.000  0.000  1.0
  O  O12  1  0.000  0.823  0.177  1.0
  O  O13  1  0.000  0.000  0.500  1.0
  O  O14  1  0.823  0.000  0.177  1.0
  O  O15  1  0.000  0.500  0.500  1.0
  O  O16  1  0.000  0.177  0.823  1.0
  O  O17  1  0.000  0.500  0.000  1.0
[/CIF]
.