data_global
_chemical_name_mineral 'Downeyite'
loop_
_publ_author_name
'McCullough J'
_journal_name_full 'Journal of the American Chemical Society'
_journal_volume 59 
_journal_year 1937
_journal_page_first 789
_journal_page_last 794
_publ_section_title
;
 The Crystal Structure of Selenium Dioxide
 _cod_database_code 1010994
;
_database_code_amcsd 0017909
_chemical_formula_sum 'Se O2'
_cell_length_a 8.353
_cell_length_b 8.353
_cell_length_c 5.051
_cell_angle_alpha 90
_cell_angle_beta 90
_cell_angle_gamma 90
_cell_volume 352.421
_exptl_crystal_density_diffrn      4.183
_symmetry_space_group_name_H-M 'P 42/m b c'
loop_
_space_group_symop_operation_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_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Se1   0.13300   0.20700   0.00000
O1   0.35800   0.85800   0.25000
O2   0.42500   0.32000   0.00000