InChI=1S/C20H9Br2O5.Hg.2Na.H2O/c21-13-5-11-17(7-15(13)23)27-18-8-16(24)14(22)6-12(18)19(11)9-3-1-2-4-10(9)20(25)26;;;;/h1-7,24H,(H,25,26);;;;1H2/q;3*+1;/p-3