Hello everyone, Does anyone know much about the crystal field splitting of the f orbitals in actinides, specifically uranium? I am doing research on the chemistry of uranium and have come across an interesting problem. U(IV) compounds undergo a transition to a non-magnetic singlet ground state at low temperatures, even though it should have two unpaired f electrons. Generally, it is accepted that this is because of thermal de-excitation of higher energy states (which is a function of U(IV)'s small crystal field splitting energy). I would like to know about the splitting of the f orbitals in different coordination environments because it seems to me that U(IV) might be able to retain it's unpaired electrons in the correct coordination environment, even at low temperatures. Thanks in advance P.S. any references you might have on this topic in general would also be appreciated, I can't seem to find much about it.