ERROR opening https://cactus.nci.nih.gov/chemical/structure/c3ccc%28CNc1ncnc2%5BnH%5Dcnc12%29cc3/file?format=sdf&get3d=True  -- c3ccc%28CNc1ncnc2%5BnH%5Dcnc12%29cc3 could not be loaded.