The Hayton group is attempting to answer fundamental question about the electronic structure of the actinide ions. In particular, we pioneered the use of NMR spectroscopy for the evaluation of covalency in these elements.  NMR spectroscopy is a widely available, but rarely used, method of measuring 5f covalency that is complementary to more established methods. Using this technique, we have quantified An-L covalency for a variety of ligand types, including chalcogenides, carbenes, alkyls, amides, and nitrides, and for a variety of isotopes, including ¹³C and ¹⁵N.  These elements are found in some of the most important actinide ligand classes, including alkyls, carbenes, polypyridines, amides, imidos, and nitrides, giving us an unprecedented window into the electronic structures of these species. Our current focus is on understanding covalency in actinide hydride and borohydride complexes using ¹H NMR spectroscopy, in collaboration with the Vlaisavljevich and Daly groups in TRU CoRE.