ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C6H16N2/c1-3-8(4-2)6-5-7/h3-7H2,1-2H3/file?format=sdf&get3d=True  -- InChI=1S/C6H16N2/c1-3-8(4-2)6-5-7/h3-7H2,1-2H3 could not be loaded.