The material structure described by HeSiO2 is High (Orthorhombic) Tridymite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure consists of eight 7440-59-7 atoms inside a SiO2 framework. In the SiO2 framework, there are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), 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(2), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a linear 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 bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_HeSiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.195
_cell_length_b   9.000
_cell_length_c   10.488
_cell_angle_alpha   55.356
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   403.397
_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
  He  He0  1  0.193  0.377  0.043  1.0
  He  He1  1  0.693  0.623  0.457  1.0
  He  He2  1  0.807  0.623  0.957  1.0
  He  He3  1  0.307  0.377  0.543  1.0
  He  He4  1  0.803  0.869  0.044  1.0
  He  He5  1  0.303  0.131  0.456  1.0
  He  He6  1  0.197  0.131  0.956  1.0
  He  He7  1  0.697  0.869  0.544  1.0
  Si  Si8  1  0.804  0.375  0.316  1.0
  Si  Si9  1  0.304  0.625  0.184  1.0
  Si  Si10  1  0.196  0.625  0.684  1.0
  Si  Si11  1  0.696  0.375  0.816  1.0
  Si  Si12  1  0.700  0.125  0.191  1.0
  Si  Si13  1  0.200  0.875  0.309  1.0
  Si  Si14  1  0.300  0.875  0.809  1.0
  Si  Si15  1  0.800  0.125  0.691  1.0
  O  O16  1  0.756  0.241  0.262  1.0
  O  O17  1  0.256  0.759  0.238  1.0
  O  O18  1  0.244  0.759  0.738  1.0
  O  O19  1  0.744  0.241  0.762  1.0
  O  O20  1  0.811  0.259  0.504  1.0
  O  O21  1  0.311  0.741  0.996  1.0
  O  O22  1  0.189  0.741  0.496  1.0
  O  O23  1  0.689  0.259  0.004  1.0
  O  O24  1  0.578  0.525  0.252  1.0
  O  O25  1  0.078  0.475  0.248  1.0
  O  O26  1  0.422  0.475  0.748  1.0
  O  O27  1  0.922  0.525  0.752  1.0
  O  O28  1  0.924  0.975  0.244  1.0
  O  O29  1  0.424  0.025  0.256  1.0
  O  O30  1  0.076  0.025  0.756  1.0
  O  O31  1  0.576  0.975  0.744  1.0
[/CIF]
.
The material structure described by HeSiO2 is High (Orthorhombic) Tridymite-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure consists of eight 7440-59-7 atoms inside a SiO2 framework. In the SiO2 framework, there are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), 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(2), and two equivalent O(4) atoms to form corner-sharing SiO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to one Si(1) and one Si(2) atom. In the second O site, O(2) is bonded in a linear 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 bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_HeSiO2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.195
_cell_length_b   9.000
_cell_length_c   10.488
_cell_angle_alpha   55.356
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   403.397
_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
  He  He0  1  0.193  0.377  0.043  1.0
  He  He1  1  0.693  0.623  0.457  1.0
  He  He2  1  0.807  0.623  0.957  1.0
  He  He3  1  0.307  0.377  0.543  1.0
  He  He4  1  0.803  0.869  0.044  1.0
  He  He5  1  0.303  0.131  0.456  1.0
  He  He6  1  0.197  0.131  0.956  1.0
  He  He7  1  0.697  0.869  0.544  1.0
  Si  Si8  1  0.804  0.375  0.316  1.0
  Si  Si9  1  0.304  0.625  0.184  1.0
  Si  Si10  1  0.196  0.625  0.684  1.0
  Si  Si11  1  0.696  0.375  0.816  1.0
  Si  Si12  1  0.700  0.125  0.191  1.0
  Si  Si13  1  0.200  0.875  0.309  1.0
  Si  Si14  1  0.300  0.875  0.809  1.0
  Si  Si15  1  0.800  0.125  0.691  1.0
  O  O16  1  0.756  0.241  0.262  1.0
  O  O17  1  0.256  0.759  0.238  1.0
  O  O18  1  0.244  0.759  0.738  1.0
  O  O19  1  0.744  0.241  0.762  1.0
  O  O20  1  0.811  0.259  0.504  1.0
  O  O21  1  0.311  0.741  0.996  1.0
  O  O22  1  0.189  0.741  0.496  1.0
  O  O23  1  0.689  0.259  0.004  1.0
  O  O24  1  0.578  0.525  0.252  1.0
  O  O25  1  0.078  0.475  0.248  1.0
  O  O26  1  0.422  0.475  0.748  1.0
  O  O27  1  0.922  0.525  0.752  1.0
  O  O28  1  0.924  0.975  0.244  1.0
  O  O29  1  0.424  0.025  0.256  1.0
  O  O30  1  0.076  0.025  0.756  1.0
  O  O31  1  0.576  0.975  0.744  1.0
[/CIF]
.