The structure described by SiO2 is quartz (alpha)-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(6), one O(7), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(6) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(7) is bonded in a distorted bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(8) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(3) atoms. In the eighth O site, O(5) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.940
_cell_length_b   13.244
_cell_length_c   13.244
_cell_angle_alpha   115.266
_cell_angle_beta   75.121
_cell_angle_gamma   75.121
_symmetry_Int_Tables_number   1
_cell_volume   687.648
_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  0.157  0.640  0.508  1.0
  Si  Si1  1  0.857  0.874  0.517  1.0
  Si  Si2  1  0.143  0.483  0.126  1.0
  Si  Si3  1  0.472  0.862  0.369  1.0
  Si  Si4  1  0.843  0.360  0.492  1.0
  Si  Si5  1  0.472  0.369  0.862  1.0
  Si  Si6  1  0.528  0.631  0.138  1.0
  Si  Si7  1  0.857  0.517  0.874  1.0
  Si  Si8  1  0.843  0.492  0.360  1.0
  Si  Si9  1  0.528  0.138  0.631  1.0
  Si  Si10  1  0.143  0.126  0.483  1.0
  Si  Si11  1  0.157  0.508  0.640  1.0
  O  O12  1  0.824  0.114  0.523  1.0
  O  O13  1  0.764  0.822  0.401  1.0
  O  O14  1  0.073  0.434  0.219  1.0
  O  O15  1  0.176  0.477  0.886  1.0
  O  O16  1  0.500  0.239  0.761  1.0
  O  O17  1  0.415  0.991  0.374  1.0
  O  O18  1  0.415  0.374  0.991  1.0
  O  O19  1  0.927  0.781  0.566  1.0
  O  O20  1  0.000  0.559  0.441  1.0
  O  O21  1  0.500  0.595  0.405  1.0
  O  O22  1  0.810  0.384  0.384  1.0
  O  O23  1  0.000  0.441  0.559  1.0
  O  O24  1  0.236  0.178  0.599  1.0
  O  O25  1  0.824  0.523  0.114  1.0
  O  O26  1  0.764  0.401  0.822  1.0
  O  O27  1  0.585  0.009  0.626  1.0
  O  O28  1  0.073  0.219  0.434  1.0
  O  O29  1  0.927  0.566  0.781  1.0
  O  O30  1  0.500  0.405  0.595  1.0
  O  O31  1  0.190  0.616  0.616  1.0
  O  O32  1  0.176  0.886  0.477  1.0
  O  O33  1  0.500  0.761  0.239  1.0
  O  O34  1  0.585  0.626  0.009  1.0
  O  O35  1  0.236  0.599  0.178  1.0
[/CIF]
.
The structure described by SiO2 is quartz (alpha)-like structured and crystallizes in the monoclinic C2/m space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(3), one O(6), one O(7), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(6) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(7) is bonded in a distorted bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(8) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the sixth O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(3) atoms. In the eighth O site, O(5) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.940
_cell_length_b   13.244
_cell_length_c   13.244
_cell_angle_alpha   115.266
_cell_angle_beta   75.121
_cell_angle_gamma   75.121
_symmetry_Int_Tables_number   1
_cell_volume   687.648
_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  0.157  0.640  0.508  1.0
  Si  Si1  1  0.857  0.874  0.517  1.0
  Si  Si2  1  0.143  0.483  0.126  1.0
  Si  Si3  1  0.472  0.862  0.369  1.0
  Si  Si4  1  0.843  0.360  0.492  1.0
  Si  Si5  1  0.472  0.369  0.862  1.0
  Si  Si6  1  0.528  0.631  0.138  1.0
  Si  Si7  1  0.857  0.517  0.874  1.0
  Si  Si8  1  0.843  0.492  0.360  1.0
  Si  Si9  1  0.528  0.138  0.631  1.0
  Si  Si10  1  0.143  0.126  0.483  1.0
  Si  Si11  1  0.157  0.508  0.640  1.0
  O  O12  1  0.824  0.114  0.523  1.0
  O  O13  1  0.764  0.822  0.401  1.0
  O  O14  1  0.073  0.434  0.219  1.0
  O  O15  1  0.176  0.477  0.886  1.0
  O  O16  1  0.500  0.239  0.761  1.0
  O  O17  1  0.415  0.991  0.374  1.0
  O  O18  1  0.415  0.374  0.991  1.0
  O  O19  1  0.927  0.781  0.566  1.0
  O  O20  1  0.000  0.559  0.441  1.0
  O  O21  1  0.500  0.595  0.405  1.0
  O  O22  1  0.810  0.384  0.384  1.0
  O  O23  1  0.000  0.441  0.559  1.0
  O  O24  1  0.236  0.178  0.599  1.0
  O  O25  1  0.824  0.523  0.114  1.0
  O  O26  1  0.764  0.401  0.822  1.0
  O  O27  1  0.585  0.009  0.626  1.0
  O  O28  1  0.073  0.219  0.434  1.0
  O  O29  1  0.927  0.566  0.781  1.0
  O  O30  1  0.500  0.405  0.595  1.0
  O  O31  1  0.190  0.616  0.616  1.0
  O  O32  1  0.176  0.886  0.477  1.0
  O  O33  1  0.500  0.761  0.239  1.0
  O  O34  1  0.585  0.626  0.009  1.0
  O  O35  1  0.236  0.599  0.178  1.0
[/CIF]
.