data_9008417
_publ_section_title
;
 The crystal structure of SeO2 at 139 and 286 K
 Note: T = 139 K
 Locality: synthetic
;
_journal_name_full               'Zeitschrift fur Kristallographie'
_journal_page_first              99
_journal_page_last               107
_journal_volume                  202
_journal_year                    1992
_chemical_formula_sum            'O2 Se'
_chemical_name_mineral           Downeyite
_space_group_IT_number           135
_symmetry_space_group_name_Hall  '-P 4c 2ab'
_symmetry_space_group_name_H-M   'P 42/m b c'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_length_a                   8.3218
_cell_length_b                   8.3218
_cell_length_c                   5.0541
_cell_volume                     350.008
_diffrn_ambient_temperature      139
_exptl_crystal_density_diffrn    4.211
_[local]_cod_chemical_formula_sum_orig 'Se O2'
_cod_database_code               9008417
loop_
_symmetry_equiv_pos_as_xyz
x,y,z
1/2-y,1/2-x,1/2+z
1/2+y,1/2+x,1/2-z
y,-x,1/2-z
-y,x,1/2+z
1/2+x,1/2-y,z
1/2-x,1/2+y,-z
x,y,-z
-x,-y,z
1/2+y,1/2+x,1/2+z
1/2-y,1/2-x,1/2-z
-y,x,1/2-z
y,-x,1/2+z
1/2-x,1/2+y,z
1/2+x,1/2-y,-z
-x,-y,-z
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
Se 0.00428 0.00540 0.00732 0.00018 0.00000 0.00000
O1 0.00919 0.00919 0.00964 0.00193 0.00217 0.00217
O2 0.00596 0.01284 0.01524 -0.00137 0.00000 0.00000
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
Se 0.13396 0.20929 0.00000 0.00570
O1 0.13752 0.36248 0.25000 0.00937
O2 -0.05789 0.17358 0.00000 0.01140
