ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C4H8N2O3/c1-4(7)9-3-5-6(2)8/h3H2,1-2H3/b6-5-/file?format=sdf&get3d=True -- InChI=1S/C4H8N2O3/c1-4(7)9-3-5-6(2)8/h3H2,1-2H3/b6-5- could not be loaded.