The structure described by SiO2 is Low Tridymite-like structured and crystallizes in the orthorhombic Imm2 space group. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(8), one O(9), and two equivalent O(6) atoms to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(10), one O(9), and two equivalent O(1) atoms to form corner-sharing SiO4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(11), one O(12), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(13), one O(14), and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. In the seventh Si site, Si(7) is bonded to two equivalent O(10) and two equivalent O(14) atoms to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to two equivalent O(12) and two equivalent O(8) atoms to form corner-sharing SiO4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a linear geometry to one Si(1) and one Si(5) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(8) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Si(3) and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent Si(5) atoms. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(8) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to two equivalent Si(6) atoms. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(7) atom. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.462
_cell_length_b   12.462
_cell_length_c   12.462
_cell_angle_alpha   144.884
_cell_angle_beta   109.886
_cell_angle_gamma   80.901
_symmetry_Int_Tables_number   1
_cell_volume   1020.782
_cell_formula_units_Z   18
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  0.383  0.391  0.403  1.0
  Si  Si1  1  0.988  0.980  0.597  1.0
  Si  Si2  1  0.383  0.980  0.991  1.0
  Si  Si3  1  0.988  0.391  0.009  1.0
  Si  Si4  1  0.744  0.336  0.995  1.0
  Si  Si5  1  0.341  0.749  0.005  1.0
  Si  Si6  1  0.744  0.749  0.408  1.0
  Si  Si7  1  0.341  0.336  0.592  1.0
  Si  Si8  1  0.150  0.948  0.203  1.0
  Si  Si9  1  0.745  0.948  0.797  1.0
  Si  Si10  1  0.498  0.798  0.700  1.0
  Si  Si11  1  0.098  0.798  0.300  1.0
  Si  Si12  1  0.116  0.409  0.293  1.0
  Si  Si13  1  0.116  0.823  0.707  1.0
  Si  Si14  1  0.487  0.281  0.794  1.0
  Si  Si15  1  0.487  0.693  0.206  1.0
  Si  Si16  1  0.368  0.868  0.500  1.0
  Si  Si17  1  0.997  0.997  0.000  1.0
  O  O18  1  0.477  0.577  0.548  1.0
  O  O19  1  0.029  0.928  0.452  1.0
  O  O20  1  0.477  0.928  0.899  1.0
  O  O21  1  0.029  0.577  0.101  1.0
  O  O22  1  0.390  0.371  0.517  1.0
  O  O23  1  0.854  0.873  0.483  1.0
  O  O24  1  0.390  0.873  0.019  1.0
  O  O25  1  0.854  0.371  0.981  1.0
  O  O26  1  0.413  0.207  0.206  1.0
  O  O27  1  0.001  0.207  0.794  1.0
  O  O28  1  0.253  0.411  0.340  1.0
  O  O29  1  0.071  0.913  0.660  1.0
  O  O30  1  0.253  0.913  0.842  1.0
  O  O31  1  0.071  0.411  0.158  1.0
  O  O32  1  0.626  0.286  0.843  1.0
  O  O33  1  0.443  0.783  0.157  1.0
  O  O34  1  0.626  0.783  0.340  1.0
  O  O35  1  0.443  0.286  0.660  1.0
  O  O36  1  0.748  0.163  0.936  1.0
  O  O37  1  0.227  0.812  0.064  1.0
  O  O38  1  0.748  0.812  0.585  1.0
  O  O39  1  0.227  0.163  0.415  1.0
  O  O40  1  0.747  0.525  0.222  1.0
  O  O41  1  0.303  0.525  0.778  1.0
  O  O42  1  0.038  0.947  0.091  1.0
  O  O43  1  0.856  0.947  0.909  1.0
  O  O44  1  0.105  0.868  0.238  1.0
  O  O45  1  0.630  0.868  0.762  1.0
  O  O46  1  0.408  0.818  0.590  1.0
  O  O47  1  0.228  0.818  0.410  1.0
  O  O48  1  0.094  0.594  0.500  1.0
  O  O49  1  0.045  0.221  0.176  1.0
  O  O50  1  0.045  0.869  0.824  1.0
  O  O51  1  0.463  0.463  0.000  1.0
  O  O52  1  0.417  0.092  0.675  1.0
  O  O53  1  0.417  0.742  0.325  1.0
[/CIF]
.
The structure described by SiO2 is Low Tridymite-like structured and crystallizes in the orthorhombic Imm2 space group. There are eight inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(5), one O(6), and one O(7) atom to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(8), one O(9), and two equivalent O(6) atoms to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(10), one O(9), and two equivalent O(1) atoms to form corner-sharing SiO4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(11), one O(12), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(13), one O(14), and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. In the seventh Si site, Si(7) is bonded to two equivalent O(10) and two equivalent O(14) atoms to form corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to two equivalent O(12) and two equivalent O(8) atoms to form corner-sharing SiO4 tetrahedra. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(4) is bonded in a linear geometry to one Si(1) and one Si(5) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(8) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Si(3) and one Si(4) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to two equivalent Si(5) atoms. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(8) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to two equivalent Si(6) atoms. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(7) atom. is represented by the CIF file [CIF]
data_SiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.462
_cell_length_b   12.462
_cell_length_c   12.462
_cell_angle_alpha   144.884
_cell_angle_beta   109.886
_cell_angle_gamma   80.901
_symmetry_Int_Tables_number   1
_cell_volume   1020.782
_cell_formula_units_Z   18
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  0.383  0.391  0.403  1.0
  Si  Si1  1  0.988  0.980  0.597  1.0
  Si  Si2  1  0.383  0.980  0.991  1.0
  Si  Si3  1  0.988  0.391  0.009  1.0
  Si  Si4  1  0.744  0.336  0.995  1.0
  Si  Si5  1  0.341  0.749  0.005  1.0
  Si  Si6  1  0.744  0.749  0.408  1.0
  Si  Si7  1  0.341  0.336  0.592  1.0
  Si  Si8  1  0.150  0.948  0.203  1.0
  Si  Si9  1  0.745  0.948  0.797  1.0
  Si  Si10  1  0.498  0.798  0.700  1.0
  Si  Si11  1  0.098  0.798  0.300  1.0
  Si  Si12  1  0.116  0.409  0.293  1.0
  Si  Si13  1  0.116  0.823  0.707  1.0
  Si  Si14  1  0.487  0.281  0.794  1.0
  Si  Si15  1  0.487  0.693  0.206  1.0
  Si  Si16  1  0.368  0.868  0.500  1.0
  Si  Si17  1  0.997  0.997  0.000  1.0
  O  O18  1  0.477  0.577  0.548  1.0
  O  O19  1  0.029  0.928  0.452  1.0
  O  O20  1  0.477  0.928  0.899  1.0
  O  O21  1  0.029  0.577  0.101  1.0
  O  O22  1  0.390  0.371  0.517  1.0
  O  O23  1  0.854  0.873  0.483  1.0
  O  O24  1  0.390  0.873  0.019  1.0
  O  O25  1  0.854  0.371  0.981  1.0
  O  O26  1  0.413  0.207  0.206  1.0
  O  O27  1  0.001  0.207  0.794  1.0
  O  O28  1  0.253  0.411  0.340  1.0
  O  O29  1  0.071  0.913  0.660  1.0
  O  O30  1  0.253  0.913  0.842  1.0
  O  O31  1  0.071  0.411  0.158  1.0
  O  O32  1  0.626  0.286  0.843  1.0
  O  O33  1  0.443  0.783  0.157  1.0
  O  O34  1  0.626  0.783  0.340  1.0
  O  O35  1  0.443  0.286  0.660  1.0
  O  O36  1  0.748  0.163  0.936  1.0
  O  O37  1  0.227  0.812  0.064  1.0
  O  O38  1  0.748  0.812  0.585  1.0
  O  O39  1  0.227  0.163  0.415  1.0
  O  O40  1  0.747  0.525  0.222  1.0
  O  O41  1  0.303  0.525  0.778  1.0
  O  O42  1  0.038  0.947  0.091  1.0
  O  O43  1  0.856  0.947  0.909  1.0
  O  O44  1  0.105  0.868  0.238  1.0
  O  O45  1  0.630  0.868  0.762  1.0
  O  O46  1  0.408  0.818  0.590  1.0
  O  O47  1  0.228  0.818  0.410  1.0
  O  O48  1  0.094  0.594  0.500  1.0
  O  O49  1  0.045  0.221  0.176  1.0
  O  O50  1  0.045  0.869  0.824  1.0
  O  O51  1  0.463  0.463  0.000  1.0
  O  O52  1  0.417  0.092  0.675  1.0
  O  O53  1  0.417  0.742  0.325  1.0
[/CIF]
.