ERROR opening https://cactus.nci.nih.gov/chemical/structure/O%3DS+%28c2nc1ccccc1n2%29+Cc3nccc+%28OCCCOC%29+c3C/file?format=sdf&get3d=True -- O%3DS+%28c2nc1ccccc1n2%29+Cc3nccc+%28OCCCOC%29+c3C could not be loaded.