Current understanding of photoelectron spectra in plutonium systems

Analysis of available photoelectron spectra from Pu compounds indicates the presence of the 5f5 multiplet, which dominates the energy scale close to the Fermi level. As shown by the LDA+U+Hubbard I calculations, its intensity scales with the admixture of the 5f6 manifold in the 5f5 ground state, which can lead to an average occupancy substantially exceeding 5.0. This admixture also leads to the suppression of magnetic order and occurrence of heavy fermion behaviour.