Chemical effects in rare gas adsorption: FLAPW calculations for Ag(001)c(2×2)-Xe

In order to investigate postulated chemical effects in adsorption of heavy rare gas atoms, we investigate the Ag(001)c(2×2)-Xe system using the full-potential linearized augmented plane-wave method. Adsorption in the on-top site is found to be favored by 8.6 meV—adsorption in this site suggests that there is a chemical contribution to the bonding. The topology of the charge density associated with the Xe 5p states clearly shows that these states are involved in a bonding interaction with the substrate states. We also show that the extra splitting of the 5p_3/2 orbitals arises from adsorbate-adsorbate interactions. It is observed that the spin-orbit interaction drastically alters the electronic, but not geometric, properties of the system.