ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCCC%28CCC%29C%28%3DO%29%5BO-%5D.%5BNa%2B%5D/file?format=sdf&get3d=True  -- CCCC%28CCC%29C%28%3DO%29%5BO-%5D.%5BNa%2B%5D could not be loaded.