Calculated optical properties of heavy metals. I. Relativistic formalism and cubic 5d metals

The formalism for calculation of the optical properties of solids within the random phase approximation and the relativistic linear muffin-tin-orbital method is presented. The method is applied to the cubic 5d metals Ta, W, Ir, Pt, and Au using the local density approximation. The band structures, the lj projected densities of states, the complex dielectric functions, the optical conductivities, and the electron energy-loss spectra are evaluated in the energy range from 0 to 30 eV. Good agreement with the experimental data is found.