The crystal structure described by SiO2 is Hydrophilite-like structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form a mixture of edge and corner-sharing SiO6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. In the second Si site, Si(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form a mixture of edge and corner-sharing SiO6 octahedra. The corner-sharing octahedral tilt angles range from 49-51°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Si(1) and two equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Si(2) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to three equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.127
_cell_length_b   5.075
_cell_length_c   6.957
_cell_angle_alpha   78.264
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   142.680
_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  0.997  0.200  0.335  1.0
  Si  Si1  1  0.000  0.000  0.000  1.0
  Si  Si2  1  0.503  0.700  0.335  1.0
  Si  Si3  1  0.500  0.500  0.000  1.0
  Si  Si4  1  0.497  0.300  0.665  1.0
  Si  Si5  1  0.003  0.800  0.665  1.0
  O  O6  1  0.787  0.766  0.889  1.0
  O  O7  1  0.772  0.960  0.222  1.0
  O  O8  1  0.768  0.101  0.554  1.0
  O  O9  1  0.732  0.601  0.554  1.0
  O  O10  1  0.728  0.460  0.222  1.0
  O  O11  1  0.713  0.266  0.889  1.0
  O  O12  1  0.287  0.734  0.111  1.0
  O  O13  1  0.272  0.540  0.778  1.0
  O  O14  1  0.268  0.399  0.446  1.0
  O  O15  1  0.232  0.899  0.446  1.0
  O  O16  1  0.228  0.040  0.778  1.0
  O  O17  1  0.213  0.234  0.111  1.0
[/CIF]
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The crystal structure described by SiO2 is Hydrophilite-like structured and crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), two equivalent O(2), and three equivalent O(3) atoms to form a mixture of edge and corner-sharing SiO6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. In the second Si site, Si(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form a mixture of edge and corner-sharing SiO6 octahedra. The corner-sharing octahedral tilt angles range from 49-51°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Si(1) and two equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Si(2) and two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to three equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.127
_cell_length_b   5.075
_cell_length_c   6.957
_cell_angle_alpha   78.264
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   142.680
_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  0.997  0.200  0.335  1.0
  Si  Si1  1  0.000  0.000  0.000  1.0
  Si  Si2  1  0.503  0.700  0.335  1.0
  Si  Si3  1  0.500  0.500  0.000  1.0
  Si  Si4  1  0.497  0.300  0.665  1.0
  Si  Si5  1  0.003  0.800  0.665  1.0
  O  O6  1  0.787  0.766  0.889  1.0
  O  O7  1  0.772  0.960  0.222  1.0
  O  O8  1  0.768  0.101  0.554  1.0
  O  O9  1  0.732  0.601  0.554  1.0
  O  O10  1  0.728  0.460  0.222  1.0
  O  O11  1  0.713  0.266  0.889  1.0
  O  O12  1  0.287  0.734  0.111  1.0
  O  O13  1  0.272  0.540  0.778  1.0
  O  O14  1  0.268  0.399  0.446  1.0
  O  O15  1  0.232  0.899  0.446  1.0
  O  O16  1  0.228  0.040  0.778  1.0
  O  O17  1  0.213  0.234  0.111  1.0
[/CIF]
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