ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/2Na.2O.Zn/q2*+1;2*-2;+2/file?format=sdf&get3d=True -- InChI=1S/2Na.2O.Zn/q2*+1;2*-2;+2 could not be loaded.