Lattice dynamics of black phosphorus

Phonon dispersion curves of black phosphorus are calculated using the force constant model, in which the valence force model is assumed for intralayer interatomic interactions and the axially symmetric force model for interlayer ones. Ten force constants in all are determined by “least-squares” fitting to optical Г-phonons and the symmetry relations between sound velocities. The phonon dispersion curves calculated are applied successfully to interpretation of experiments on the first and second order Raman spectra, effective Debye temperature, and inelastic neutron scattering. Large discrepancy between the calculated and observed linear compressibilities exists.