ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3Dc2c1ccccc1c4n%5BnH%5Dc3cccc2c34/file?format=sdf&get3d=True  -- O%3Dc2c1ccccc1c4n%5BnH%5Dc3cccc2c34 could not be loaded.