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 obtain ed. Using an optimized pseudopotential to model the ion-electron inter action requires only a modest number of plane waves, and the calculate d phonon dispersion curves are in excellent agreement with experiment. The force constant tenser is studied in detail and is compared with t hose obtained from Born-Von Karman fits to the experimental Excellent agreement with experiment is found when the range of interaction is ta ken to fourth neighbors, however, longer-ranged interactions need to b e included to accurately determine the lattice specific heat.