The material structure described by SiO2 is Low Tridymite-like structured and crystallizes in the monoclinic C2/m space group. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(6), one O(8), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(1), one O(5), one O(7), and one O(8) atom to form corner-sharing SiO4 tetrahedra. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(4) atoms. In the sixth O site, O(6) is bonded in a linear geometry to two equivalent Si(3) atoms. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to two equivalent Si(3) atoms. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.660
_cell_length_b   11.547
_cell_length_c   11.547
_cell_angle_alpha   71.718
_cell_angle_beta   80.617
_cell_angle_gamma   80.617
_symmetry_Int_Tables_number   1
_cell_volume   949.922
_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  0.228  0.365  0.958  1.0
  Si  Si1  1  0.772  0.042  0.635  1.0
  Si  Si2  1  0.772  0.635  0.042  1.0
  Si  Si3  1  0.228  0.958  0.365  1.0
  Si  Si4  1  0.124  0.639  0.866  1.0
  Si  Si5  1  0.876  0.134  0.361  1.0
  Si  Si6  1  0.876  0.361  0.134  1.0
  Si  Si7  1  0.124  0.866  0.639  1.0
  Si  Si8  1  0.800  0.101  0.874  1.0
  Si  Si9  1  0.200  0.126  0.899  1.0
  Si  Si10  1  0.200  0.899  0.126  1.0
  Si  Si11  1  0.800  0.874  0.101  1.0
  Si  Si12  1  0.597  0.263  0.032  1.0
  Si  Si13  1  0.403  0.968  0.737  1.0
  Si  Si14  1  0.403  0.737  0.968  1.0
  Si  Si15  1  0.597  0.032  0.263  1.0
  O  O16  1  0.754  0.333  0.047  1.0
  O  O17  1  0.246  0.953  0.667  1.0
  O  O18  1  0.246  0.667  0.953  1.0
  O  O19  1  0.754  0.047  0.333  1.0
  O  O20  1  0.767  0.111  0.737  1.0
  O  O21  1  0.233  0.263  0.889  1.0
  O  O22  1  0.233  0.889  0.263  1.0
  O  O23  1  0.767  0.737  0.111  1.0
  O  O24  1  0.917  0.659  0.922  1.0
  O  O25  1  0.083  0.078  0.341  1.0
  O  O26  1  0.083  0.341  0.078  1.0
  O  O27  1  0.917  0.922  0.659  1.0
  O  O28  1  0.178  0.499  0.864  1.0
  O  O29  1  0.822  0.136  0.501  1.0
  O  O30  1  0.822  0.501  0.136  1.0
  O  O31  1  0.178  0.864  0.499  1.0
  O  O32  1  0.549  0.158  0.158  1.0
  O  O33  1  0.451  0.842  0.842  1.0
  O  O34  1  0.000  0.875  0.125  1.0
  O  O35  1  0.000  0.125  0.875  1.0
  O  O36  1  0.422  0.999  0.359  1.0
  O  O37  1  0.578  0.641  0.001  1.0
  O  O38  1  0.578  0.001  0.641  1.0
  O  O39  1  0.422  0.359  0.999  1.0
  O  O40  1  0.662  0.921  0.202  1.0
  O  O41  1  0.338  0.798  0.079  1.0
  O  O42  1  0.338  0.079  0.798  1.0
  O  O43  1  0.662  0.202  0.921  1.0
  O  O44  1  0.769  0.964  0.964  1.0
  O  O45  1  0.231  0.036  0.036  1.0
  O  O46  1  0.152  0.728  0.728  1.0
  O  O47  1  0.848  0.272  0.272  1.0
[/CIF]
.
The material structure described by SiO2 is Low Tridymite-like structured and crystallizes in the monoclinic C2/m space group. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(6), one O(8), and one O(9) atom to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(1), one O(5), one O(7), and one O(8) atom to form corner-sharing SiO4 tetrahedra. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(4) atoms. In the sixth O site, O(6) is bonded in a linear geometry to two equivalent Si(3) atoms. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to two equivalent Si(3) atoms. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.660
_cell_length_b   11.547
_cell_length_c   11.547
_cell_angle_alpha   71.718
_cell_angle_beta   80.617
_cell_angle_gamma   80.617
_symmetry_Int_Tables_number   1
_cell_volume   949.922
_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  0.228  0.365  0.958  1.0
  Si  Si1  1  0.772  0.042  0.635  1.0
  Si  Si2  1  0.772  0.635  0.042  1.0
  Si  Si3  1  0.228  0.958  0.365  1.0
  Si  Si4  1  0.124  0.639  0.866  1.0
  Si  Si5  1  0.876  0.134  0.361  1.0
  Si  Si6  1  0.876  0.361  0.134  1.0
  Si  Si7  1  0.124  0.866  0.639  1.0
  Si  Si8  1  0.800  0.101  0.874  1.0
  Si  Si9  1  0.200  0.126  0.899  1.0
  Si  Si10  1  0.200  0.899  0.126  1.0
  Si  Si11  1  0.800  0.874  0.101  1.0
  Si  Si12  1  0.597  0.263  0.032  1.0
  Si  Si13  1  0.403  0.968  0.737  1.0
  Si  Si14  1  0.403  0.737  0.968  1.0
  Si  Si15  1  0.597  0.032  0.263  1.0
  O  O16  1  0.754  0.333  0.047  1.0
  O  O17  1  0.246  0.953  0.667  1.0
  O  O18  1  0.246  0.667  0.953  1.0
  O  O19  1  0.754  0.047  0.333  1.0
  O  O20  1  0.767  0.111  0.737  1.0
  O  O21  1  0.233  0.263  0.889  1.0
  O  O22  1  0.233  0.889  0.263  1.0
  O  O23  1  0.767  0.737  0.111  1.0
  O  O24  1  0.917  0.659  0.922  1.0
  O  O25  1  0.083  0.078  0.341  1.0
  O  O26  1  0.083  0.341  0.078  1.0
  O  O27  1  0.917  0.922  0.659  1.0
  O  O28  1  0.178  0.499  0.864  1.0
  O  O29  1  0.822  0.136  0.501  1.0
  O  O30  1  0.822  0.501  0.136  1.0
  O  O31  1  0.178  0.864  0.499  1.0
  O  O32  1  0.549  0.158  0.158  1.0
  O  O33  1  0.451  0.842  0.842  1.0
  O  O34  1  0.000  0.875  0.125  1.0
  O  O35  1  0.000  0.125  0.875  1.0
  O  O36  1  0.422  0.999  0.359  1.0
  O  O37  1  0.578  0.641  0.001  1.0
  O  O38  1  0.578  0.001  0.641  1.0
  O  O39  1  0.422  0.359  0.999  1.0
  O  O40  1  0.662  0.921  0.202  1.0
  O  O41  1  0.338  0.798  0.079  1.0
  O  O42  1  0.338  0.079  0.798  1.0
  O  O43  1  0.662  0.202  0.921  1.0
  O  O44  1  0.769  0.964  0.964  1.0
  O  O45  1  0.231  0.036  0.036  1.0
  O  O46  1  0.152  0.728  0.728  1.0
  O  O47  1  0.848  0.272  0.272  1.0
[/CIF]
.