data_global _chemical_name_mineral 'Birnessite' loop_ _publ_author_name 'Lopano C L' 'Heaney P J' 'Post J E' 'Hanson J' 'Komarneni S' _journal_name_full 'American Mineralogist' _journal_volume 92 _journal_year 2007 _journal_page_first 380 _journal_page_last 387 _publ_section_title ; Time-resolved structural analysis of K-and Ba-exchange reactions with synthetic Na-birnessite using synchrotron X-ray diffraction Sample: K-birnessite ; _database_code_amcsd 0004277 _chemical_compound_source 'Synthetic' _chemical_formula_sum 'K.23 Mn O2.776 H1.552' _cell_length_a 5.1371 _cell_length_b 2.8476 _cell_length_c 7.2131 _cell_angle_alpha 89.96 _cell_angle_beta 100.75 _cell_angle_gamma 89.702 _cell_volume 103.663 _exptl_crystal_density_diffrn 3.521 _symmetry_space_group_name_H-M 'C -1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2+y,z' '-x,-y,-z' '1/2-x,1/2-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_U_iso_or_equiv K -0.18350 0.60990 0.49310 0.11500 0.06730 Mn 0.00000 0.00000 0.00000 1.00000 0.00580 O 0.37170 0.03310 0.13480 1.00000 0.03180 Wat -0.18350 0.60990 0.49310 0.38800 0.06730