The material described by SiO2 is Low Tridymite-like structured and crystallizes in the tetragonal I-42m space group. Si(1) is bonded to one O(1), one O(2), 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 linear geometry to two equivalent Si(1) atoms. In the second O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(2) 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   7.674
_cell_length_b   7.674
_cell_length_c   7.674
_cell_angle_alpha   106.716
_cell_angle_beta   106.716
_cell_angle_gamma   115.134
_symmetry_Int_Tables_number   1
_cell_volume   345.290
_cell_formula_units_Z   8
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  0.477  0.119  0.232  1.0
  Si  Si1  1  0.887  0.245  0.768  1.0
  Si  Si2  1  0.119  0.477  0.232  1.0
  Si  Si3  1  0.881  0.113  0.358  1.0
  Si  Si4  1  0.755  0.523  0.642  1.0
  Si  Si5  1  0.245  0.887  0.768  1.0
  Si  Si6  1  0.113  0.881  0.358  1.0
  Si  Si7  1  0.523  0.755  0.642  1.0
  O  O8  1  0.000  0.283  0.283  1.0
  O  O9  1  0.083  0.374  0.000  1.0
  O  O10  1  0.623  0.016  0.253  1.0
  O  O11  1  0.000  0.717  0.717  1.0
  O  O12  1  0.374  0.083  0.000  1.0
  O  O13  1  0.984  0.238  0.607  1.0
  O  O14  1  0.238  0.984  0.607  1.0
  O  O15  1  0.626  0.626  0.709  1.0
  O  O16  1  0.762  0.369  0.747  1.0
  O  O17  1  0.717  0.000  0.717  1.0
  O  O18  1  0.016  0.623  0.253  1.0
  O  O19  1  0.377  0.631  0.393  1.0
  O  O20  1  0.283  0.000  0.283  1.0
  O  O21  1  0.631  0.377  0.393  1.0
  O  O22  1  0.917  0.917  0.291  1.0
  O  O23  1  0.369  0.762  0.747  1.0
[/CIF]
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The material described by SiO2 is Low Tridymite-like structured and crystallizes in the tetragonal I-42m space group. Si(1) is bonded to one O(1), one O(2), 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 linear geometry to two equivalent Si(1) atoms. In the second O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(2) 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   7.674
_cell_length_b   7.674
_cell_length_c   7.674
_cell_angle_alpha   106.716
_cell_angle_beta   106.716
_cell_angle_gamma   115.134
_symmetry_Int_Tables_number   1
_cell_volume   345.290
_cell_formula_units_Z   8
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  0.477  0.119  0.232  1.0
  Si  Si1  1  0.887  0.245  0.768  1.0
  Si  Si2  1  0.119  0.477  0.232  1.0
  Si  Si3  1  0.881  0.113  0.358  1.0
  Si  Si4  1  0.755  0.523  0.642  1.0
  Si  Si5  1  0.245  0.887  0.768  1.0
  Si  Si6  1  0.113  0.881  0.358  1.0
  Si  Si7  1  0.523  0.755  0.642  1.0
  O  O8  1  0.000  0.283  0.283  1.0
  O  O9  1  0.083  0.374  0.000  1.0
  O  O10  1  0.623  0.016  0.253  1.0
  O  O11  1  0.000  0.717  0.717  1.0
  O  O12  1  0.374  0.083  0.000  1.0
  O  O13  1  0.984  0.238  0.607  1.0
  O  O14  1  0.238  0.984  0.607  1.0
  O  O15  1  0.626  0.626  0.709  1.0
  O  O16  1  0.762  0.369  0.747  1.0
  O  O17  1  0.717  0.000  0.717  1.0
  O  O18  1  0.016  0.623  0.253  1.0
  O  O19  1  0.377  0.631  0.393  1.0
  O  O20  1  0.283  0.000  0.283  1.0
  O  O21  1  0.631  0.377  0.393  1.0
  O  O22  1  0.917  0.917  0.291  1.0
  O  O23  1  0.369  0.762  0.747  1.0
[/CIF]
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