Embedding effects on core level shifts of surface cluster models

Core eigenvalue spectra of naked and embedded cluster models of the Li (100) surface are compared to each other and to the core level energies of a five-layer 2D-periodic slab model. The electronic structure calculations have been carried out in the frame work of density functional theory, cluster embedding was performed by means of the moderately large embedded cluster scheme. The results for naked clusters reflect the inhomogeneous environment of the atoms due to artificial model boundaries. On the other hand, embedding yields discrete spectra that exhibit a close similarity to the energetic distribution of the slab core energies.