Optical and photoemission properties of alkali-metal nitrates

The reflection and photoemission spectra of sodium, potassium, rubidium, and cesium nitrates were recorded in the energy interval 5–11.5 eV. The band structure, density of electronic states, and optical functions are calculated within the context of the density functional theory by the pseudopotential method in the basis set of localized sp3d5 atomic pseudoorbitals expanded in the plane waves. The experimental and theoretical data are compared, and it is shown that the calculated spectral dependences of the imaginary part of the complex dielectric constant and combined density of states are in satisfactory agreement with the observed reflection and photoemission spectra, which suggests that the processes governed by these phenomena have the zone nature.