The structure described by SiO2 is High (Orthorhombic) Tridymite-like structured and crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to two equivalent O(4) and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are five 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(2) is bonded in a linear geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Si(2) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.346
_cell_length_b   13.346
_cell_length_c   13.346
_cell_angle_alpha   92.221
_cell_angle_beta   92.221
_cell_angle_gamma   157.295
_symmetry_Int_Tables_number   1
_cell_volume   899.577
_cell_formula_units_Z   16
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  0.774  0.658  0.432  1.0
  Si  Si1  1  0.342  0.774  0.116  1.0
  Si  Si2  1  0.658  0.226  0.884  1.0
  Si  Si3  1  0.774  0.342  0.116  1.0
  Si  Si4  1  0.226  0.658  0.884  1.0
  Si  Si5  1  0.226  0.342  0.568  1.0
  Si  Si6  1  0.658  0.774  0.432  1.0
  Si  Si7  1  0.342  0.226  0.568  1.0
  Si  Si8  1  0.121  0.000  0.121  1.0
  Si  Si9  1  0.000  0.121  0.121  1.0
  Si  Si10  1  0.000  0.879  0.879  1.0
  Si  Si11  1  0.879  0.000  0.879  1.0
  Si  Si12  1  0.719  0.500  0.219  1.0
  Si  Si13  1  0.500  0.719  0.219  1.0
  Si  Si14  1  0.500  0.281  0.781  1.0
  Si  Si15  1  0.281  0.500  0.781  1.0
  O  O16  1  0.693  0.693  0.386  1.0
  O  O17  1  0.307  0.693  0.000  1.0
  O  O18  1  0.693  0.307  0.000  1.0
  O  O19  1  0.307  0.307  0.614  1.0
  O  O20  1  0.067  0.933  0.500  1.0
  O  O21  1  0.567  0.067  0.133  1.0
  O  O22  1  0.933  0.433  0.867  1.0
  O  O23  1  0.433  0.567  0.500  1.0
  O  O24  1  0.933  0.067  0.500  1.0
  O  O25  1  0.433  0.933  0.867  1.0
  O  O26  1  0.067  0.567  0.133  1.0
  O  O27  1  0.567  0.433  0.500  1.0
  O  O28  1  0.769  0.571  0.340  1.0
  O  O29  1  0.429  0.769  0.198  1.0
  O  O30  1  0.571  0.231  0.802  1.0
  O  O31  1  0.769  0.429  0.198  1.0
  O  O32  1  0.231  0.571  0.802  1.0
  O  O33  1  0.231  0.429  0.660  1.0
  O  O34  1  0.571  0.769  0.340  1.0
  O  O35  1  0.429  0.231  0.660  1.0
  O  O36  1  0.420  0.250  0.170  1.0
  O  O37  1  0.250  0.420  0.170  1.0
  O  O38  1  0.250  0.080  0.830  1.0
  O  O39  1  0.920  0.750  0.170  1.0
  O  O40  1  0.580  0.750  0.830  1.0
  O  O41  1  0.080  0.250  0.830  1.0
  O  O42  1  0.750  0.920  0.170  1.0
  O  O43  1  0.750  0.580  0.830  1.0
  O  O44  1  0.071  0.071  0.143  1.0
  O  O45  1  0.929  0.071  0.000  1.0
  O  O46  1  0.071  0.929  0.000  1.0
  O  O47  1  0.929  0.929  0.857  1.0
[/CIF]
.
The structure described by SiO2 is High (Orthorhombic) Tridymite-like structured and crystallizes in the tetragonal I4/mmm space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to two equivalent O(4) and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to two equivalent O(3) and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are five 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(2) is bonded in a linear geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Si(2) and one Si(3) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.346
_cell_length_b   13.346
_cell_length_c   13.346
_cell_angle_alpha   92.221
_cell_angle_beta   92.221
_cell_angle_gamma   157.295
_symmetry_Int_Tables_number   1
_cell_volume   899.577
_cell_formula_units_Z   16
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  0.774  0.658  0.432  1.0
  Si  Si1  1  0.342  0.774  0.116  1.0
  Si  Si2  1  0.658  0.226  0.884  1.0
  Si  Si3  1  0.774  0.342  0.116  1.0
  Si  Si4  1  0.226  0.658  0.884  1.0
  Si  Si5  1  0.226  0.342  0.568  1.0
  Si  Si6  1  0.658  0.774  0.432  1.0
  Si  Si7  1  0.342  0.226  0.568  1.0
  Si  Si8  1  0.121  0.000  0.121  1.0
  Si  Si9  1  0.000  0.121  0.121  1.0
  Si  Si10  1  0.000  0.879  0.879  1.0
  Si  Si11  1  0.879  0.000  0.879  1.0
  Si  Si12  1  0.719  0.500  0.219  1.0
  Si  Si13  1  0.500  0.719  0.219  1.0
  Si  Si14  1  0.500  0.281  0.781  1.0
  Si  Si15  1  0.281  0.500  0.781  1.0
  O  O16  1  0.693  0.693  0.386  1.0
  O  O17  1  0.307  0.693  0.000  1.0
  O  O18  1  0.693  0.307  0.000  1.0
  O  O19  1  0.307  0.307  0.614  1.0
  O  O20  1  0.067  0.933  0.500  1.0
  O  O21  1  0.567  0.067  0.133  1.0
  O  O22  1  0.933  0.433  0.867  1.0
  O  O23  1  0.433  0.567  0.500  1.0
  O  O24  1  0.933  0.067  0.500  1.0
  O  O25  1  0.433  0.933  0.867  1.0
  O  O26  1  0.067  0.567  0.133  1.0
  O  O27  1  0.567  0.433  0.500  1.0
  O  O28  1  0.769  0.571  0.340  1.0
  O  O29  1  0.429  0.769  0.198  1.0
  O  O30  1  0.571  0.231  0.802  1.0
  O  O31  1  0.769  0.429  0.198  1.0
  O  O32  1  0.231  0.571  0.802  1.0
  O  O33  1  0.231  0.429  0.660  1.0
  O  O34  1  0.571  0.769  0.340  1.0
  O  O35  1  0.429  0.231  0.660  1.0
  O  O36  1  0.420  0.250  0.170  1.0
  O  O37  1  0.250  0.420  0.170  1.0
  O  O38  1  0.250  0.080  0.830  1.0
  O  O39  1  0.920  0.750  0.170  1.0
  O  O40  1  0.580  0.750  0.830  1.0
  O  O41  1  0.080  0.250  0.830  1.0
  O  O42  1  0.750  0.920  0.170  1.0
  O  O43  1  0.750  0.580  0.830  1.0
  O  O44  1  0.071  0.071  0.143  1.0
  O  O45  1  0.929  0.071  0.000  1.0
  O  O46  1  0.071  0.929  0.000  1.0
  O  O47  1  0.929  0.929  0.857  1.0
[/CIF]
.