ERROR opening https://cactus.nci.nih.gov/chemical/structure/c1ccc%28cc1%29%5BSe%5D%5BSe%5Dc2ccccc2/file?format=sdf&get3d=True  -- c1ccc%28cc1%29%5BSe%5D%5BSe%5Dc2ccccc2 could not be loaded.