data_9006301
_publ_section_title
;
 Framework silica structures generated using simulated annealing
 with a potential energy function based on an H6Si2O7 molecule
 Sample: 18
;
_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           24
_symmetry_space_group_name_Hall  'I 2b 2c'
_symmetry_space_group_name_H-M   'I 21 21 21'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_length_a                   4.1154
_cell_length_b                   4.4201
_cell_length_c                   15.5724
_cell_volume                     283.269
_exptl_crystal_density_diffrn    2.818
_[local]_cod_chemical_formula_sum_orig 'Si O2'
_cod_database_code               9006301
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
1/2+x,1/2+y,1/2+z
-x,1/2+y,1/2-z
1/2-x,+y,-z
1/2+x,1/2-y,-z
+x,-y,1/2-z
1/2-x,-y,1/2+z
-x,1/2-y,+z
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Si1 0.00000 0.75000 0.81134
Si2 0.00000 0.75000 0.06175
O1 0.23818 0.56935 0.12709
O2 0.32240 0.00000 0.25000
O3 0.25000 0.05307 0.50000
