Theoretical investigation of electronic structure, electric field gradients, and photoemission of PuCoGa5 and PuRhGa5 superconductors

We report electronic structure calculations of PuCoGa5 and PuRhGa5 superconductors. The band structure, electric field gradients, and Fermi surface topologies were investigated using two methods of correlated band theory, namely the conventional static mean-field LDA+U and the local density matrix approximation (LDMA). The latter is based on the Hubbard-I approximation and includes intra-atomic dynamical correlations in a self-consistent manner. Our results show that although LDA+U and LDMA calculations do not significantly modify the Fermi surface topologies compared to LDA, they do lead to a substantial reduction of the f character of the electronic states at the Fermi energy. The calculations indicate presence of a pseudogap in the electronic spectrum. We achieve a good agreement between calculated and experimental nuclear quadrupolar resonance frequencies and a fairly good agreement between calculated and experimental photoemission spectra. Our findings can be important for the theory of superconductivity in PuCoGa5 and related compounds.