ERROR opening https://cactus.nci.nih.gov/chemical/structure/%26%2391%3BC-%26%2393%3B%23N.%26%2391%3BAu%2B%26%2393%3B/file?format=sdf&get3d=True -- %26%2391%3BC-%26%2393%3B%23N.%26%2391%3BAu%2B%26%2393%3B could not be loaded.