ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C5H3N3/c6-3-5-4-7-1-2-8-5/h1-2,4H/file?format=sdf&get3d=True  -- InChI=1S/C5H3N3/c6-3-5-4-7-1-2-8-5/h1-2,4H could not be loaded.