  The lattice dynamics of AgPd, Ni55Pd45, Ni95Pt05, and Cu0.715Pd0.285
intermetallic have been investigated using the DFT calculation. The phonon
dispersions and phonon densities of states along for two symmetry directions
are calculated by Weighted Dynamical Matrix (WDM) and compared with virtual
crystal approximation (VCA), supercell approach, and inelastic neutron
scattering experimental results. The impact of mass, force-constant
fluctuation, and Ag concentration on lattice dynamics of AgPd are discussed,
and a comparison between WDM and Supercell approach is performed. The averaged
first Nearest Neighbor (1NN) force constants between various pairs of atoms in
these intermetallic are obtained from the WDM approach. Based on our results,
the WDM approach agrees well with the supercell approach, and neutron
scattering experimental data. VCA overestimates in some cases and
underestimates, in other cases, the first-principles frequencies.
