First-principles calculations of phonons and Raman spectra in the Hg3Te2Cl2 crystals

This paper presents a systematic first-principles study of phonons and Raman spectra of cubic Hg3Te2Cl2 within a framework of DFT in the GGA/PBE approximation. The phonon dispersion, total and partial density of vibrational states for Hg3Te2Cl2 crystals are analyzed. The identification of the vibrational modes at the Brillouin zone center is conducted and discussed in details. The first-principles calculated Raman-active phonon frequencies and simulated Raman spectra are compared with experimental data. The assignment of the phonon lines to define atomic vibrations was made on the basis of their symmetries in close comparison with results of lattice-dynamical calculations. Satisfactory agreement is obtained with experimental mode frequencies.