MULTIELECTRON AND MULTISTATE EFFECTS IN THE CHARGE-TRANSFER PROCESSESBETWEEN OXYGEN AND METAL-SURFACES

Oxygen atoms and molecules and their negative ions have an electronic structure containing a few equivalent outer electrons. In the course o f an atom (molecule)-metal surface collision, each of them can partici pate in charge transfer processes. It is shown that this multi-electro n aspect has to be taken into account, it generates multi-state and po larization effects. The consequences for the resonant charge transfer process are discussed and two examples are discussed: polarization eff ects in sputtering of O- ions and quenching of oxygen singlet states. A generalisation to other systems and electronic structures is present ed.