ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DC1N%28CCc3c1c2ccccc2n3C%29Cc4ncnc4C/file?format=sdf&get3d=True  -- O%3DC1N%28CCc3c1c2ccccc2n3C%29Cc4ncnc4C could not be loaded.