The material structure described by SiO2 crystallizes in the orthorhombic I2_12_12_1 space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) 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(1) and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 120 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   8.374
_cell_length_b   8.374
_cell_length_c   8.374
_cell_angle_alpha   150.605
_cell_angle_beta   147.655
_cell_angle_gamma   44.266
_symmetry_Int_Tables_number   1
_cell_volume   153.768
_cell_formula_units_Z   4
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  0.187  0.437  0.750  1.0
  Si  Si1  1  0.440  0.690  0.750  1.0
  Si  Si2  1  0.060  0.810  0.250  1.0
  Si  Si3  1  0.313  0.063  0.250  1.0
  O  O4  1  0.288  0.608  0.155  1.0
  O  O5  1  0.212  0.367  0.320  1.0
  O  O6  1  0.547  0.892  0.180  1.0
  O  O7  1  0.071  0.750  0.821  1.0
  O  O8  1  0.750  0.593  0.843  1.0
  O  O9  1  0.250  0.907  0.657  1.0
  O  O10  1  0.429  0.250  0.679  1.0
  O  O11  1  0.953  0.133  0.345  1.0
[/CIF]
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The material structure described by SiO2 crystallizes in the orthorhombic I2_12_12_1 space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) 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(1) and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a bent 120 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   8.374
_cell_length_b   8.374
_cell_length_c   8.374
_cell_angle_alpha   150.605
_cell_angle_beta   147.655
_cell_angle_gamma   44.266
_symmetry_Int_Tables_number   1
_cell_volume   153.768
_cell_formula_units_Z   4
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  0.187  0.437  0.750  1.0
  Si  Si1  1  0.440  0.690  0.750  1.0
  Si  Si2  1  0.060  0.810  0.250  1.0
  Si  Si3  1  0.313  0.063  0.250  1.0
  O  O4  1  0.288  0.608  0.155  1.0
  O  O5  1  0.212  0.367  0.320  1.0
  O  O6  1  0.547  0.892  0.180  1.0
  O  O7  1  0.071  0.750  0.821  1.0
  O  O8  1  0.750  0.593  0.843  1.0
  O  O9  1  0.250  0.907  0.657  1.0
  O  O10  1  0.429  0.250  0.679  1.0
  O  O11  1  0.953  0.133  0.345  1.0
[/CIF]
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