data_global
_chemical_name_mineral 'Selenium'
loop_
_publ_author_name
'Wyckoff R W G'
_journal_name_full 'Crystal Structures'
_journal_volume 1 
_journal_year 1963
_journal_page_first 7
_journal_page_last 83
_publ_section_title
;
 Second edition. Interscience Publishers, New York, New York
 Sample is the alpha form of the monoclinic phase
;
_database_code_amcsd 0011259
_chemical_formula_sum 'Se'
_cell_length_a 9.05
_cell_length_b 9.07
_cell_length_c 11.61
_cell_angle_alpha 90
_cell_angle_beta 90.767
_cell_angle_gamma 90
_cell_volume 952.904
_exptl_crystal_density_diffrn      4.403
_symmetry_space_group_name_H-M 'P 1 21/n 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2-y,1/2+z'
  '1/2-x,1/2+y,1/2-z'
  '-x,-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Se1   0.32100   0.48600   0.23700
Se2   0.42700   0.66400   0.35700
Se3   0.31700   0.63700   0.53500
Se4   0.13400   0.82000   0.55600
Se5  -0.08100   0.68600   0.52100
Se6  -0.15600   0.73300   0.32800
Se7  -0.08400   0.52000   0.22900
Se8   0.13100   0.59700   0.13400