data_global _chemical_name_mineral 'Acanthite' loop_ _publ_author_name 'Frueh A J' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 110 _journal_year 1958 _journal_page_first 136 _journal_page_last 144 _publ_section_title ; The crystallography of silver sulfide, Ag2S ; _database_code_amcsd 0010584 _chemical_compound_source 'Freiberg, Saxony, Germany' _chemical_formula_sum 'Ag2 S' _cell_length_a 4.23 _cell_length_b 6.91 _cell_length_c 7.87 _cell_angle_alpha 90 _cell_angle_beta 99.58 _cell_angle_gamma 90 _cell_volume 226.827 _exptl_crystal_density_diffrn 7.256 _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 AgI 0.75800 0.01500 0.30500 AgII 0.28500 0.32000 0.43500 S 0.35900 0.23900 0.13400