The compound described by SiO2 is High (Orthorhombic) Tridymite structured and crystallizes in the monoclinic P2_1 space group. Si(1,2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1,2) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Si(1,2) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1,2) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(1,2) atoms. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.180
_cell_length_b   4.931
_cell_length_c   5.005
_cell_angle_alpha   61.632
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   177.625
_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  0.938  0.581  0.651  1.0
  Si  Si1  1  0.564  0.746  0.694  1.0
  Si  Si2  1  0.438  0.419  0.349  1.0
  Si  Si3  1  0.064  0.254  0.306  1.0
  O  O4  1  0.946  0.451  0.410  1.0
  O  O5  1  0.751  0.651  0.691  1.0
  O  O6  1  0.545  0.109  0.466  1.0
  O  O7  1  0.511  0.678  0.031  1.0
  O  O8  1  0.446  0.549  0.590  1.0
  O  O9  1  0.251  0.349  0.309  1.0
  O  O10  1  0.045  0.891  0.534  1.0
  O  O11  1  0.011  0.322  0.969  1.0
[/CIF]
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The compound described by SiO2 is High (Orthorhombic) Tridymite structured and crystallizes in the monoclinic P2_1 space group. Si(1,2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1,2) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Si(1,2) atoms. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1,2) atoms. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to two equivalent Si(1,2) atoms. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.180
_cell_length_b   4.931
_cell_length_c   5.005
_cell_angle_alpha   61.632
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   177.625
_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  0.938  0.581  0.651  1.0
  Si  Si1  1  0.564  0.746  0.694  1.0
  Si  Si2  1  0.438  0.419  0.349  1.0
  Si  Si3  1  0.064  0.254  0.306  1.0
  O  O4  1  0.946  0.451  0.410  1.0
  O  O5  1  0.751  0.651  0.691  1.0
  O  O6  1  0.545  0.109  0.466  1.0
  O  O7  1  0.511  0.678  0.031  1.0
  O  O8  1  0.446  0.549  0.590  1.0
  O  O9  1  0.251  0.349  0.309  1.0
  O  O10  1  0.045  0.891  0.534  1.0
  O  O11  1  0.011  0.322  0.969  1.0
[/CIF]
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