ERROR opening https://cactus.nci.nih.gov/chemical/structure/CCN%28CC%29CC%5BSe%5DP%28%3DO%29%28CC%29OCC/file?format=sdf&get3d=True  -- CCN%28CC%29CC%5BSe%5DP%28%3DO%29%28CC%29OCC could not be loaded.