Electronic, elastic and phonon properties of the rock-salt LaSb and YSb

The electronic structures and elastic constants of LaSb and YSb are calculated using an ab initio pseudopotential scheme within the generalized gradient approximation. In agreement with experimental studies, it has been found that the upper valence bands in LaSb are characterized by Sb- 5p and La- 5d states. Our calculated elastic constants for LaSb are compared with available experimental data. A linear- response approach to density functional theory is used to derive phonon dispersion curves and the density of states for LaSb and YSb. Our phonon results for LaSb are in good agreement with experimental data. Frequency differences between phonon modes in these materials are discussed in terms of differences involving total mass, reduced mass and the lattice constant