ERROR opening https://cactus.nci.nih.gov/chemical/structure/n1ccn%28c1%29C%28c3ccc%28c2ccccc2%29cc3%29c4ccccc4/file?format=sdf&get3d=True -- n1ccn%28c1%29C%28c3ccc%28c2ccccc2%29cc3%29c4ccccc4 could not be loaded.