The material described by SiO2 is quartz (alpha)-like structured and crystallizes in the monoclinic C2/c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) 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(2) 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 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.842
_cell_length_b   7.306
_cell_length_c   7.348
_cell_angle_alpha   73.264
_cell_angle_beta   70.762
_cell_angle_gamma   70.646
_symmetry_Int_Tables_number   1
_cell_volume   226.862
_cell_formula_units_Z   6
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  0.424  0.321  0.346  1.0
  Si  Si1  1  0.091  0.179  0.154  1.0
  Si  Si2  1  0.576  0.679  0.654  1.0
  Si  Si3  1  0.909  0.821  0.846  1.0
  Si  Si4  1  0.974  0.250  0.750  1.0
  Si  Si5  1  0.026  0.750  0.250  1.0
  O  O6  1  0.714  0.442  0.690  1.0
  O  O7  1  0.846  0.058  0.810  1.0
  O  O8  1  0.286  0.558  0.310  1.0
  O  O9  1  0.154  0.942  0.190  1.0
  O  O10  1  0.272  0.223  0.567  1.0
  O  O11  1  0.063  0.277  0.933  1.0
  O  O12  1  0.214  0.731  0.688  1.0
  O  O13  1  0.633  0.769  0.812  1.0
  O  O14  1  0.786  0.269  0.312  1.0
  O  O15  1  0.367  0.231  0.188  1.0
  O  O16  1  0.937  0.723  0.067  1.0
  O  O17  1  0.728  0.777  0.433  1.0
[/CIF]
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The material described by SiO2 is quartz (alpha)-like structured and crystallizes in the monoclinic C2/c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) 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(2) 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 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.842
_cell_length_b   7.306
_cell_length_c   7.348
_cell_angle_alpha   73.264
_cell_angle_beta   70.762
_cell_angle_gamma   70.646
_symmetry_Int_Tables_number   1
_cell_volume   226.862
_cell_formula_units_Z   6
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  0.424  0.321  0.346  1.0
  Si  Si1  1  0.091  0.179  0.154  1.0
  Si  Si2  1  0.576  0.679  0.654  1.0
  Si  Si3  1  0.909  0.821  0.846  1.0
  Si  Si4  1  0.974  0.250  0.750  1.0
  Si  Si5  1  0.026  0.750  0.250  1.0
  O  O6  1  0.714  0.442  0.690  1.0
  O  O7  1  0.846  0.058  0.810  1.0
  O  O8  1  0.286  0.558  0.310  1.0
  O  O9  1  0.154  0.942  0.190  1.0
  O  O10  1  0.272  0.223  0.567  1.0
  O  O11  1  0.063  0.277  0.933  1.0
  O  O12  1  0.214  0.731  0.688  1.0
  O  O13  1  0.633  0.769  0.812  1.0
  O  O14  1  0.786  0.269  0.312  1.0
  O  O15  1  0.367  0.231  0.188  1.0
  O  O16  1  0.937  0.723  0.067  1.0
  O  O17  1  0.728  0.777  0.433  1.0
[/CIF]
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