The structure described by SiO2 crystallizes in the orthorhombic Imm2 space group. There are four inequivalent Si sites. In the first Si site, Si(1,4) is bonded to one O(11), one O(7), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(10), one O(12), one O(2), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(5,6) is bonded to one O(4), one O(6), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing SiO4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(5,6) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Si(1,4) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(5,6) atom. In the fourth O site, O(4) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to two equivalent Si(2) atoms. In the sixth O site, O(6) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the seventh O site, O(7) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Si(1,4) and one Si(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to two equivalent Si(2) atoms. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to two equivalent Si(3) atoms. In the eleventh O site, O(11) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to two equivalent Si(3) atoms. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.363
_cell_length_b   15.363
_cell_length_c   15.363
_cell_angle_alpha   109.768
_cell_angle_beta   109.556
_cell_angle_gamma   109.091
_symmetry_Int_Tables_number   1
_cell_volume   2791.318
_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  0.773  0.305  0.467  1.0
  Si  Si1  1  0.548  0.001  0.707  1.0
  Si  Si2  1  0.706  0.999  0.547  1.0
  Si  Si3  1  0.548  0.841  0.547  1.0
  Si  Si4  1  0.959  0.499  0.300  1.0
  Si  Si5  1  0.706  0.159  0.707  1.0
  Si  Si6  1  0.791  0.305  0.096  1.0
  Si  Si7  1  0.959  0.659  0.460  1.0
  Si  Si8  1  0.162  0.695  0.467  1.0
  Si  Si9  1  0.714  0.197  0.911  1.0
  Si  Si10  1  0.791  0.695  0.486  1.0
  Si  Si11  1  0.801  0.341  0.300  1.0
  Si  Si12  1  0.714  0.803  0.518  1.0
  Si  Si13  1  0.345  0.804  0.541  1.0
  Si  Si14  1  0.737  0.196  0.541  1.0
  Si  Si15  1  0.801  0.501  0.460  1.0
  O  O16  1  0.608  0.772  0.531  1.0
  O  O17  1  0.898  0.424  0.170  1.0
  O  O18  1  0.419  0.772  0.494  1.0
  O  O19  1  0.807  0.788  0.596  1.0
  O  O20  1  0.722  0.075  0.494  1.0
  O  O21  1  0.760  0.923  0.531  1.0
  O  O22  1  0.898  0.728  0.474  1.0
  O  O23  1  0.746  0.272  0.170  1.0
  O  O24  1  0.593  0.918  0.675  1.0
  O  O25  1  0.608  0.077  0.837  1.0
  O  O26  1  0.758  0.082  0.675  1.0
  O  O27  1  0.698  0.710  0.408  1.0
  O  O28  1  0.807  0.212  0.019  1.0
  O  O29  1  0.662  0.213  0.448  1.0
  O  O30  1  0.722  0.228  0.646  1.0
  O  O31  1  0.419  0.925  0.646  1.0
  O  O32  1  0.235  0.787  0.448  1.0
  O  O33  1  0.787  0.273  0.361  1.0
  O  O34  1  0.579  0.917  0.496  1.0
  O  O35  1  0.698  0.290  0.988  1.0
  O  O36  1  0.746  0.576  0.474  1.0
  O  O37  1  0.914  0.582  0.332  1.0
  O  O38  1  0.089  0.575  0.361  1.0
  O  O39  1  0.089  0.727  0.514  1.0
  O  O40  1  0.787  0.425  0.514  1.0
  O  O41  1  0.848  0.288  0.560  1.0
  O  O42  1  0.928  0.583  0.511  1.0
  O  O43  1  0.749  0.418  0.332  1.0
  O  O44  1  0.760  0.228  0.837  1.0
  O  O45  1  0.579  0.083  0.662  1.0
  O  O46  1  0.928  0.417  0.345  1.0
  O  O47  1  0.272  0.712  0.560  1.0
[/CIF]
.
The structure described by SiO2 crystallizes in the orthorhombic Imm2 space group. There are four inequivalent Si sites. In the first Si site, Si(1,4) is bonded to one O(11), one O(7), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(3), one O(5), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(10), one O(12), one O(2), and one O(8) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(5,6) is bonded to one O(4), one O(6), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing SiO4 tetrahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(5,6) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Si(1,4) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Si(2) and one Si(5,6) atom. In the fourth O site, O(4) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to two equivalent Si(2) atoms. In the sixth O site, O(6) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the seventh O site, O(7) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the eighth O site, O(8) is bonded in a bent 120 degrees geometry to one Si(1,4) and one Si(3) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to two equivalent Si(2) atoms. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to two equivalent Si(3) atoms. In the eleventh O site, O(11) is bonded in an L-shaped geometry to one Si(1,4) and one Si(5,6) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to two equivalent Si(3) atoms. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.363
_cell_length_b   15.363
_cell_length_c   15.363
_cell_angle_alpha   109.768
_cell_angle_beta   109.556
_cell_angle_gamma   109.091
_symmetry_Int_Tables_number   1
_cell_volume   2791.318
_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  0.773  0.305  0.467  1.0
  Si  Si1  1  0.548  0.001  0.707  1.0
  Si  Si2  1  0.706  0.999  0.547  1.0
  Si  Si3  1  0.548  0.841  0.547  1.0
  Si  Si4  1  0.959  0.499  0.300  1.0
  Si  Si5  1  0.706  0.159  0.707  1.0
  Si  Si6  1  0.791  0.305  0.096  1.0
  Si  Si7  1  0.959  0.659  0.460  1.0
  Si  Si8  1  0.162  0.695  0.467  1.0
  Si  Si9  1  0.714  0.197  0.911  1.0
  Si  Si10  1  0.791  0.695  0.486  1.0
  Si  Si11  1  0.801  0.341  0.300  1.0
  Si  Si12  1  0.714  0.803  0.518  1.0
  Si  Si13  1  0.345  0.804  0.541  1.0
  Si  Si14  1  0.737  0.196  0.541  1.0
  Si  Si15  1  0.801  0.501  0.460  1.0
  O  O16  1  0.608  0.772  0.531  1.0
  O  O17  1  0.898  0.424  0.170  1.0
  O  O18  1  0.419  0.772  0.494  1.0
  O  O19  1  0.807  0.788  0.596  1.0
  O  O20  1  0.722  0.075  0.494  1.0
  O  O21  1  0.760  0.923  0.531  1.0
  O  O22  1  0.898  0.728  0.474  1.0
  O  O23  1  0.746  0.272  0.170  1.0
  O  O24  1  0.593  0.918  0.675  1.0
  O  O25  1  0.608  0.077  0.837  1.0
  O  O26  1  0.758  0.082  0.675  1.0
  O  O27  1  0.698  0.710  0.408  1.0
  O  O28  1  0.807  0.212  0.019  1.0
  O  O29  1  0.662  0.213  0.448  1.0
  O  O30  1  0.722  0.228  0.646  1.0
  O  O31  1  0.419  0.925  0.646  1.0
  O  O32  1  0.235  0.787  0.448  1.0
  O  O33  1  0.787  0.273  0.361  1.0
  O  O34  1  0.579  0.917  0.496  1.0
  O  O35  1  0.698  0.290  0.988  1.0
  O  O36  1  0.746  0.576  0.474  1.0
  O  O37  1  0.914  0.582  0.332  1.0
  O  O38  1  0.089  0.575  0.361  1.0
  O  O39  1  0.089  0.727  0.514  1.0
  O  O40  1  0.787  0.425  0.514  1.0
  O  O41  1  0.848  0.288  0.560  1.0
  O  O42  1  0.928  0.583  0.511  1.0
  O  O43  1  0.749  0.418  0.332  1.0
  O  O44  1  0.760  0.228  0.837  1.0
  O  O45  1  0.579  0.083  0.662  1.0
  O  O46  1  0.928  0.417  0.345  1.0
  O  O47  1  0.272  0.712  0.560  1.0
[/CIF]
.