data_9000253
_chemical_name 'Acanthite'
loop_
_publ_author_name
'Wiegers G A'
_journal_name_full "American Mineralogist"
_journal_volume 56
_journal_year 1971
_journal_page_first 1882
_journal_page_last 1888
_publ_section_title
;
 The crystal structure of the low-temperature form of silver selenide
;
_chemical_formula_sum 'Ag2 S'
_cell_length_a 4.229
_cell_length_b 6.931
_cell_length_c 7.862
_cell_angle_alpha 90
_cell_angle_beta 99.61
_cell_angle_gamma 90
_cell_volume 227.211
_symmetry_space_group_name_H-M 'P 1 21/n 1'
loop_
_symmetry_equiv_pos_as_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
Ag1   0.28500   0.32000   0.43500
Ag2   0.75800   0.01500   0.30500
S   0.35900   0.23900   0.13400