data_global _chemical_name_mineral 'Tarapacaite' loop_ _publ_author_name 'Zachariasen W' 'Ziegler G' _journal_name_full 'Zeitschrift fur Kristallographie' _journal_volume 80 _journal_year 1931 _journal_page_first 164 _journal_page_last 173 _publ_section_title ; The crystal structure of potassium chromate K2 Cr O4 _cod_database_code 1011186 ; _database_code_amcsd 0018061 _chemical_formula_sum 'K2 Cr O4' _cell_length_a 5.92 _cell_length_b 10.4 _cell_length_c 7.61 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _cell_volume 468.532 _exptl_crystal_density_diffrn 2.753 _symmetry_space_group_name_H-M 'P m c n' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2-x,y,z' '1/2+x,-y,-z' '1/2+x,1/2+y,1/2-z' '1/2-x,1/2-y,1/2+z' 'x,1/2-y,1/2+z' '-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 K1 0.25000 0.08300 0.35500 K2 0.25000 -0.30600 0.50000 Cr1 0.25000 0.08300 -0.23100 O1 0.25000 0.08300 -0.01900 O2 0.25000 -0.06100 -0.30000 O3 0.02800 0.15600 -0.30000