ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C6H4N2O/c7-4-5-2-1-3-8-6(5)9/h1-3H,(H,8,9)/file?format=sdf&get3d=True  -- InChI=1S/C6H4N2O/c7-4-5-2-1-3-8-6(5)9/h1-3H,(H,8,9) could not be loaded.