data_9006290
_chemical_name 'SiO2'
loop_
_publ_author_name
'Boisen M B'
'Gibbs G V'
'Bukowinski M S T'
_journal_name_full "Physics and Chemistry of Minerals"
_journal_volume 21
_journal_year 1994
_journal_page_first 269
_journal_page_last 284
_publ_section_title
;
 Framework silica structures generated using simulated annealing
 with a potential energy function based on an H6Si2O7 molecule
 Sample: 7
;
_chemical_formula_sum 'Si O2'
_cell_length_a 7.4953
_cell_length_b 8.6203
_cell_length_c 4.7305
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 305.646
_symmetry_space_group_name_H-M 'C 2 2 21'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  '-x,y,1/2-z'
  '1/2-x,1/2+y,1/2-z'
  'x,-y,-z'
  '1/2+x,1/2-y,-z'
  '-x,-y,1/2+z'
  '1/2-x,1/2-y,1/2+z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si   0.19691   0.15247   0.35535
O1   0.31542   0.20927   0.08746
O2   0.00000   0.10526   0.25000
O3   0.71315   0.00000   0.00000