data_9006289
_publ_section_title
;
 Framework silica structures generated using simulated annealing
 with a potential energy function based on an H6Si2O7 molecule
 Sample: 6
;
_journal_name_full               'Physics and Chemistry of Minerals'
_journal_page_first              269
_journal_page_last               284
_journal_volume                  21
_journal_year                    1994
_chemical_formula_structural     SiO2
_chemical_formula_sum            'O2 Si'
_space_group_IT_number           46
_symmetry_space_group_name_Hall  'I 2 -2a'
_symmetry_space_group_name_H-M   'I m a 2'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_length_a                   10.2170
_cell_length_b                   7.9579
_cell_length_c                   4.9565
_cell_volume                     402.993
_exptl_crystal_density_diffrn    1.981
_[local]_cod_chemical_formula_sum_orig 'Si O2'
_cod_database_code               9006289
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
1/2+x,1/2+y,1/2+z
1/2+x,-y,z
+x,1/2-y,1/2+z
1/2-x,y,z
-x,1/2+y,1/2+z
-x,-y,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 0.10183 0.35660 0.50000
O1 0.57933 0.69059 0.18477
O2 0.75000 0.92453 0.04157
O3 0.00000 0.50000 0.59431
