Phonon spectrum La$_{2}$Zr$_{2}$O$_{7}$: ab initio calculation

Crystal structure and phonon spectrum of La$_{2}$Zr$_{2}$O$_{7}$ were studied within the framework of density functional theory and MO LKAO approach. The calculations were performed by using hybrid functionals that takes into account both local and nonlocal (in the Hartree–Fock formalism) exchange. The frequencies, types, and intensities of Raman and IR modes are determined. The elastic constants have been calculated too. The calculations were performed in the CRYSTAL17 program intended for simulating periodic structures in the MO LCAO approximation.