  The shape evolution of two-dimensional islands under electromigration-driven
periphery diffusion is studied by kinetic Monte Carlo (KMC) simulations and
continuum theory. The energetics of the KMC model is adapted to the Cu(100)
surface, and the continuum model is matched to the KMC model by a suitably
parametrized choice of the orientation-dependent step stiffness and step atom
mobility. At 700 K shape oscillations predicted by continuum theory are
quantitatively verified by the KMC simulations, while at 500 K qualitative
differences between the two modeling approaches are found.
