First-principles determination of the interatomic-force-constant tensor of Au

Using the plane-wave-based linear response method recently developed, the interatomic-force-constant tensor for the noble metal Au is obtained. Using an optimized pseudopotential to model the ion-electron interaction requires only a modest number of plane waves, and the calculated phonon dispersion curves are in excellent agreement with experiment. The force-constant tensor is studied in detail and is compared with those obtained from Born--Von Karman fits to the experimental data. Excellent agreement with experiment is found when the range of interaction is taken to fourth neighbors, however, longer-ranged interactions need to be included to accurately determine the lattice specific heat.