The material described by SiO2 crystallizes in the orthorhombic Pcca space group. Si(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four 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(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) 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   4.719
_cell_length_b   7.123
_cell_length_c   9.775
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   328.570
_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  0.227  0.424  0.602  1.0
  Si  Si1  1  0.227  0.076  0.102  1.0
  Si  Si2  1  0.227  0.924  0.398  1.0
  Si  Si3  1  0.227  0.576  0.898  1.0
  Si  Si4  1  0.773  0.924  0.898  1.0
  Si  Si5  1  0.773  0.076  0.602  1.0
  Si  Si6  1  0.773  0.424  0.102  1.0
  Si  Si7  1  0.773  0.576  0.398  1.0
  O  O8  1  0.000  0.500  0.000  1.0
  O  O9  1  0.663  0.500  0.250  1.0
  O  O10  1  0.500  0.000  0.000  1.0
  O  O11  1  0.000  0.750  0.339  1.0
  O  O12  1  0.500  0.000  0.500  1.0
  O  O13  1  0.000  0.250  0.661  1.0
  O  O14  1  0.000  0.250  0.161  1.0
  O  O15  1  0.663  0.000  0.750  1.0
  O  O16  1  0.000  0.750  0.839  1.0
  O  O17  1  0.500  0.500  0.500  1.0
  O  O18  1  0.000  0.000  0.500  1.0
  O  O19  1  0.337  0.000  0.250  1.0
  O  O20  1  0.500  0.500  0.000  1.0
  O  O21  1  0.337  0.500  0.750  1.0
  O  O22  1  0.000  0.000  0.000  1.0
  O  O23  1  0.000  0.500  0.500  1.0
[/CIF]
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The material described by SiO2 crystallizes in the orthorhombic Pcca space group. Si(1) is bonded in a distorted see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four 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(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) 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   4.719
_cell_length_b   7.123
_cell_length_c   9.775
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   328.570
_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  0.227  0.424  0.602  1.0
  Si  Si1  1  0.227  0.076  0.102  1.0
  Si  Si2  1  0.227  0.924  0.398  1.0
  Si  Si3  1  0.227  0.576  0.898  1.0
  Si  Si4  1  0.773  0.924  0.898  1.0
  Si  Si5  1  0.773  0.076  0.602  1.0
  Si  Si6  1  0.773  0.424  0.102  1.0
  Si  Si7  1  0.773  0.576  0.398  1.0
  O  O8  1  0.000  0.500  0.000  1.0
  O  O9  1  0.663  0.500  0.250  1.0
  O  O10  1  0.500  0.000  0.000  1.0
  O  O11  1  0.000  0.750  0.339  1.0
  O  O12  1  0.500  0.000  0.500  1.0
  O  O13  1  0.000  0.250  0.661  1.0
  O  O14  1  0.000  0.250  0.161  1.0
  O  O15  1  0.663  0.000  0.750  1.0
  O  O16  1  0.000  0.750  0.839  1.0
  O  O17  1  0.500  0.500  0.500  1.0
  O  O18  1  0.000  0.000  0.500  1.0
  O  O19  1  0.337  0.000  0.250  1.0
  O  O20  1  0.500  0.500  0.000  1.0
  O  O21  1  0.337  0.500  0.750  1.0
  O  O22  1  0.000  0.000  0.000  1.0
  O  O23  1  0.000  0.500  0.500  1.0
[/CIF]
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