ERROR opening https://cactus.nci.nih.gov/chemical/structure/N.NS%28%26%2361%3BO%29%28%26%2361%3BO%29O/file?format=sdf&get3d=True -- N.NS%28%26%2361%3BO%29%28%26%2361%3BO%29O could not be loaded.