Coverage dependence of the work function of Li adsorbed on Ru(0 0 1): ab initio studies within DFT

In this paper we present calculations of the work function change upon Li adsorption on a Ru(0 0 1) surface. In the past a theoretical and experimental investigation of this system in connection with NMR studies showed a rather large discrepancy between the theoretical and experimental results for the work function change. We have performed calculations for the system Li/Ru(0 0 1) for a variety of Li coverages ranging from very low coverages (Θ=1/9) to very high coverages (Θ=1). We show in this paper that calculations with the FLAPW-DFT method for slab geometries give (nearly) perfect agreement with new experimental results for that system, thus demonstrating the power of modern ab initio density functional methods.