ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC4N3CCc2c%28nc1ccccc12%29C3N%28c5ccccc45%29C/file?format=sdf&get3d=True  -- O%3DC4N3CCc2c%28nc1ccccc12%29C3N%28c5ccccc45%29C could not be loaded.