Comparison of the electronic structure of CsPbCl3, PcCl2, and CsCaCl3 on the basis of optical spectroscopy data

Mirror reflection spectra were taken in the energy region of E <= 10.5 eV and optical constants were calculated using the subtractive Kramers-Kronig technique. The imaginary part of the dielectric constant epsilon2 and the effective number of (optical) electrons nsub(eff) have been treated in the energy range of 0 to E. The epsilon2 spectrum represents the joint density of states and nsub(eff) spectra represents the number of valence electrons. Spectra of the optical constants have been analyzed for comparing the electronic structure of CsPbCl3, PbCl2, and CsCaCl3 ionic crystals. CsPbCl3 has an unusual structure of the valence band