ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3Dc1%5BnH%5Dc2%5BnH%5Dncc2c%28%3DO%29%5BnH%5D1/file?format=sdf&get3d=True  -- O%3Dc1%5BnH%5Dc2%5BnH%5Dncc2c%28%3DO%29%5BnH%5D1 could not be loaded.