ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI%3DInChI%26%2361%3B1S/Mg.Se/q%2B2%26%2359%3B-2/file?format=sdf&get3d=True  -- InChI%3DInChI%26%2361%3B1S/Mg.Se/q%2B2%26%2359%3B-2 could not be loaded.