EXTRACTING CONVERGENT SURFACE ENERGIES FROM SLAB CALCULATIONS

The formation energy of a solid surface can be extracted from slab cal culations if the bulk energy per atom is known. It has been pointed ou t previously that the resulting surface energy will diverge with slab thickness if the bulk energy is in error, in the context of calculatio ns which used different methods to study the bulk and slab systems. We show here that this result is equally relevant for state-of-the-art c omputational methods which carefully treat bulk and slab systems in th e same way. Here we compare different approaches, and present a soluti on to the problem that eliminates the divergence and leads to rapidly convergent and accurate surface energies.