Birnessite Lopano C L, Heaney P J, Post J E, Hanson J, Komarneni S American Mineralogist 92 (2007) 380-387 Time-resolved structural analysis of K-and Ba-exchange reactions with synthetic Na-birnessite using synchrotron X-ray diffraction Locality: synthetic Sample: Na-birnessite _database_code_amcsd 0004276 5.1780 2.8509 7.3344 89.45 103.18 89.91 C-1 atom x y z occ Uiso Na -.0270 .3154 .4885 .145 .0726 Mn 0 0 0 .0045 O .3686 -.0241 .1307 .0138 Wat -.0270 .3154 .4885 .3453 .0726