First-principles theory of surface thermodynamics and kinetics

Understanding the complex behavior of particles at surfaces requires detail ed knowledge of both macroscopic and microscopic processes that take place; also certain phenomena depend critically on temperature and gas pressure. To link these processes we combine state-of-the-art microscopic, and macros copic phenomenological, theories. We apply our theory to the O/Ru(0001) sys tem and calculate thermal desorption spectra, heat of adsorption, and the s urface phase diagram. The agreement with experiment provides validity for o ur approach which thus identifies the way for a predictive simulation of su rface thermodynamics and kinetics.