ERROR opening https://cactus.nci.nih.gov/chemical/structure/c5occc5-c%28cc1nc4%29ccc1n4-c2cc%28ccc2%29-n3cncc3/file?format=sdf&get3d=True  -- c5occc5-c%28cc1nc4%29ccc1n4-c2cc%28ccc2%29-n3cncc3 could not be loaded.