EXTRA-ATOMIC RELAXATION IN SURFACE SYSTEMS

The extra-atomic relaxation R(ea) in surface systems consists of the polarization E(pol), image charge potentials E(z) and charge transfer contributions E(q). The theory is given for polarization calculations in surface systems of molecules and gases, which form molecular lattices in the solid state. Calculations for extra-atomic relaxation are performed for 1-2-3-4 layered systems Xe/Pd(xyz), where (xyz) = (100), (110) and (111) planes as well as for 1-2-3 layered systems A/Ag(111) or AI(111), where A is Ne, Ar, Kr, Xe. Formulae are obtained for non-metallic substrate and calculations are performed for 1-2-3 layered systems of Ar, Kr and Xe on graphite. E(pol) and E(z) are the main contributors to R(ea) values. For the core levels theory agrees with experiment on average within 0.1-0.2 eV. The theory is applied for valence levels of simple molecules such as CO and N2 adsorbed on metallic and non-metallic substrate.