4. MO Theory of Heterodiatomic Molecules. We consider the molecule KrF+ in the gas phase, which can be prepared under suitable conditions. (a) Draw a qualitative MO diagram and occupy it with electrons, including the indication of spin. Indicate the LUMO and HOMO of the molecule. (b) What's the bond order of the molecule? (c) Is the character of the HOMO more like Kr or F? (d) In your MO diagram, qualitatively indicate the energy of free electrons and use arrows to indicate the ionization energy and electron affinity. (e) Could you, in theory, prepare the molecule in both spin singlet and spin triplet states? If so, would the energy of the single and triplet be different