data_global
_amcsd_formula_title '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: 23
;
_database_code_amcsd 0007888
_chemical_formula_sum 'Si O2'
_cell_length_a 4.1605
_cell_length_b 4.1294
_cell_length_c 7.4211
_cell_angle_alpha 90
_cell_angle_beta 101.3752
_cell_angle_gamma 90
_cell_volume 124.993
_exptl_crystal_density_diffrn      3.193
_symmetry_space_group_name_H-M 'P 1 2 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '-x,y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si1   0.18244   0.00000   0.69651
Si2   0.38098   0.58564   0.17797
O1   0.02399   0.75200   0.18927
O2   0.50000   0.73859   0.00000
O3   0.38562   0.71473   0.64074
O4   0.00000   0.15907   0.50000
O5   0.48963   0.20196   0.18802