data_9006292
_publ_section_title
;
 Framework silica structures generated using simulated annealing
 with a potential energy function based on an H6Si2O7 molecule
 Sample: 9
;
_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           15
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
_cell_angle_alpha                90
_cell_angle_beta                 112.2654
_cell_angle_gamma                90
_cell_length_a                   11.1032
_cell_length_b                   7.8989
_cell_length_c                   4.9771
_cell_volume                     403.960
_exptl_crystal_density_diffrn    1.976
_[local]_cod_chemical_formula_sum_orig 'Si O2'
_cod_database_code               9006292
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,1/2-z
1/2-x,1/2+y,1/2-z
-x,-y,-z
1/2-x,1/2-y,-z
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si 0.64566 0.60868 0.83039
O1 0.00000 0.81716 0.25000
O2 0.83439 0.94282 0.46534
O3 0.25001 0.75000 0.50000
