The material described by SiO2 crystallizes in the tetragonal P-42_1c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 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 two equivalent Si(2) atoms. In the third O site, O(3) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.593
_cell_length_b   11.593
_cell_length_c   5.192
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   697.878
_cell_formula_units_Z   16
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  0.156  0.076  0.989  1.0
  Si  Si1  1  0.597  0.200  0.723  1.0
  Si  Si2  1  0.656  0.424  0.511  1.0
  Si  Si3  1  0.576  0.656  0.489  1.0
  Si  Si4  1  0.700  0.097  0.223  1.0
  Si  Si5  1  0.924  0.156  0.011  1.0
  Si  Si6  1  0.344  0.576  0.511  1.0
  Si  Si7  1  0.403  0.800  0.723  1.0
  Si  Si8  1  0.903  0.700  0.777  1.0
  Si  Si9  1  0.800  0.597  0.277  1.0
  Si  Si10  1  0.300  0.903  0.223  1.0
  Si  Si11  1  0.097  0.300  0.777  1.0
  Si  Si12  1  0.200  0.403  0.277  1.0
  Si  Si13  1  0.424  0.344  0.489  1.0
  Si  Si14  1  0.844  0.924  0.989  1.0
  Si  Si15  1  0.076  0.844  0.011  1.0
  O  O16  1  0.820  0.817  0.792  1.0
  O  O17  1  0.183  0.820  0.208  1.0
  O  O18  1  0.860  0.609  0.999  1.0
  O  O19  1  0.609  0.140  0.001  1.0
  O  O20  1  0.619  0.544  0.666  1.0
  O  O21  1  0.235  0.539  0.330  1.0
  O  O22  1  0.265  0.039  0.170  1.0
  O  O23  1  0.119  0.956  0.834  1.0
  O  O24  1  0.456  0.619  0.334  1.0
  O  O25  1  0.539  0.765  0.670  1.0
  O  O26  1  0.381  0.456  0.666  1.0
  O  O27  1  0.956  0.881  0.166  1.0
  O  O28  1  0.765  0.461  0.330  1.0
  O  O29  1  0.180  0.183  0.792  1.0
  O  O30  1  0.817  0.180  0.208  1.0
  O  O31  1  0.461  0.235  0.670  1.0
  O  O32  1  0.109  0.360  0.499  1.0
  O  O33  1  0.891  0.640  0.499  1.0
  O  O34  1  0.317  0.320  0.292  1.0
  O  O35  1  0.039  0.735  0.830  1.0
  O  O36  1  0.683  0.680  0.292  1.0
  O  O37  1  0.044  0.119  0.166  1.0
  O  O38  1  0.640  0.109  0.501  1.0
  O  O39  1  0.360  0.891  0.501  1.0
  O  O40  1  0.961  0.265  0.830  1.0
  O  O41  1  0.735  0.961  0.170  1.0
  O  O42  1  0.881  0.044  0.834  1.0
  O  O43  1  0.320  0.683  0.708  1.0
  O  O44  1  0.680  0.317  0.708  1.0
  O  O45  1  0.544  0.381  0.334  1.0
  O  O46  1  0.391  0.860  0.001  1.0
  O  O47  1  0.140  0.391  0.999  1.0
[/CIF]
.
The material described by SiO2 crystallizes in the tetragonal P-42_1c space group. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 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 two equivalent Si(2) atoms. In the third O site, O(3) is bonded in a bent 120 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.593
_cell_length_b   11.593
_cell_length_c   5.192
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   697.878
_cell_formula_units_Z   16
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  0.156  0.076  0.989  1.0
  Si  Si1  1  0.597  0.200  0.723  1.0
  Si  Si2  1  0.656  0.424  0.511  1.0
  Si  Si3  1  0.576  0.656  0.489  1.0
  Si  Si4  1  0.700  0.097  0.223  1.0
  Si  Si5  1  0.924  0.156  0.011  1.0
  Si  Si6  1  0.344  0.576  0.511  1.0
  Si  Si7  1  0.403  0.800  0.723  1.0
  Si  Si8  1  0.903  0.700  0.777  1.0
  Si  Si9  1  0.800  0.597  0.277  1.0
  Si  Si10  1  0.300  0.903  0.223  1.0
  Si  Si11  1  0.097  0.300  0.777  1.0
  Si  Si12  1  0.200  0.403  0.277  1.0
  Si  Si13  1  0.424  0.344  0.489  1.0
  Si  Si14  1  0.844  0.924  0.989  1.0
  Si  Si15  1  0.076  0.844  0.011  1.0
  O  O16  1  0.820  0.817  0.792  1.0
  O  O17  1  0.183  0.820  0.208  1.0
  O  O18  1  0.860  0.609  0.999  1.0
  O  O19  1  0.609  0.140  0.001  1.0
  O  O20  1  0.619  0.544  0.666  1.0
  O  O21  1  0.235  0.539  0.330  1.0
  O  O22  1  0.265  0.039  0.170  1.0
  O  O23  1  0.119  0.956  0.834  1.0
  O  O24  1  0.456  0.619  0.334  1.0
  O  O25  1  0.539  0.765  0.670  1.0
  O  O26  1  0.381  0.456  0.666  1.0
  O  O27  1  0.956  0.881  0.166  1.0
  O  O28  1  0.765  0.461  0.330  1.0
  O  O29  1  0.180  0.183  0.792  1.0
  O  O30  1  0.817  0.180  0.208  1.0
  O  O31  1  0.461  0.235  0.670  1.0
  O  O32  1  0.109  0.360  0.499  1.0
  O  O33  1  0.891  0.640  0.499  1.0
  O  O34  1  0.317  0.320  0.292  1.0
  O  O35  1  0.039  0.735  0.830  1.0
  O  O36  1  0.683  0.680  0.292  1.0
  O  O37  1  0.044  0.119  0.166  1.0
  O  O38  1  0.640  0.109  0.501  1.0
  O  O39  1  0.360  0.891  0.501  1.0
  O  O40  1  0.961  0.265  0.830  1.0
  O  O41  1  0.735  0.961  0.170  1.0
  O  O42  1  0.881  0.044  0.834  1.0
  O  O43  1  0.320  0.683  0.708  1.0
  O  O44  1  0.680  0.317  0.708  1.0
  O  O45  1  0.544  0.381  0.334  1.0
  O  O46  1  0.391  0.860  0.001  1.0
  O  O47  1  0.140  0.391  0.999  1.0
[/CIF]
.