Structural, magnetic, electronic and optical properties of PuC and PuC_0.75: A hybrid density functional study

We perform first principles calculations to investigate the structural, magnetic, electronic and optical properties of PuC and PuC_0.75. Furthermore, we examine the influence of carbon non-stoichiometry on plutonium monocarbide. For the treatment of strongly correlated electrons, the hybrid density functionals like PBE0, Fock-0.25 are used and we compare the results with the generalized gradient approximation (GGA), local density approximation (LDA), LDA + U and experimental ones. The optimized lattice constant a₀ = 4.961 Å for PuC in the Fock-0.25 scheme is the most close to the experimental data. The ground states of PuC and PuC_0.75 are found to be anti-ferromagnetic. Our results indicate that additional removal of a C atom make lattice contract and new DOS peak appear in the near-Fermi region. We also compute and compare the optical properties of PuC and PuC_0.75. The difference in optical properties between PuC and PuC_0.75 should also be the influence of carbon vacancies.