Theoretical study of structural features and optical properties of the Hg 3 S 2 Cl 2 polymorphs

The interrelation between structural and optical properties of the Hg 3 S 2 Cl 2 polymorphs have been theoretically investigated. This paper presents the results of calculations of the refractive indices and reflection coefficients for (α), (β), (γ) – Hg 3 S 2 Cl 2 crystalline phases using the Harrison bonding-orbital method. The refractive indices in the spectral region far from the absorption edge were determined within the generalized single-oscillator model. The Hartree-Fock values for the valence levels were used for evaluation the energies of filled electronic states in Hg 3 S 2 Cl 2 crystals. By analyzing the polarizability and susceptibility χ it is possible to calculate the refractive index and reflection coefficient; moreover the performed calculations demonstrate a satisfactory agreement with experimental results.