ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC1N%28%5BH%5D%29c2ccccc2C%28c3ccccc3%29%3DNC1/file?format=sdf&get3d=True  -- O%3DC1N%28%5BH%5D%29c2ccccc2C%28c3ccccc3%29%3DNC1 could not be loaded.