Ab initio studies on the electronic structure of CeSi5

We investigated the electronic properties of CeSi5 by band structure calculation based on the density functional theory within LDA, LDA+U, and fully relativistic schemes. The calculated band structure scheme shows that the spin–orbit coupling splits the Ce 4f states into three manifolds. When the on-site Coulomb potential is added to the Ce-derived 4f orbitals, the degeneracy between the f orbitals would be lifted and they are split into lower Hubbard bands and upper Hubbard bands. It was found that quasiparticle mass enhancement inferred by comparing γγ to the density of states (DOS) at the Fermi level indicates the effective mass of CeSi5 is enhanced with the fully relativistic results.