Optical properties of polyvalent metals in the solid and liquid state: lead

Recently we proposed a semiphenomenological theory for the calculation of the optical properties of polyvalent metals. In this paper, we apply it to the heavy metal lead and show that, in contrast to the preceding paper, no fitting parameter is basically necessary. The general agreement between experimental results and theoretical curves is satisfactory for all properties in both the solid and the liquid state. The optical properties in the liquid state are more similar to those of the solid state than to those of a free-electron system and therefore cannot be described by a simple Drude model.