ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%5BS%2B2%5D%28%5BO-%5D%29%28%5BO-%5D%29O/file?format=sdf&get3d=True  -- O%5BS%2B2%5D%28%5BO-%5D%29%28%5BO-%5D%29O could not be loaded.