Newns-Anderson resonance

It is also interesting to consider charge-transfer models developed primarily for metal surfaces. There are clear parallels to the metal oxide case in that there is an interaction between discrete molecular orbitals on one side, and electronic bands on the other side of the interface. The Newns-Anderson model [118] qualitatively accounts for the interactions between adsorbed atoms and metal surfaces. The model is based on resonance of adatom levels with a substrate band. In particular, the model considers an energy shift in the adatom level, as well as a broadening of that level. The width of the level is taken as a measure of the interaction strength with the substrate bands [118]. Also femtosecond electron dynamics have been studied at electrode interfaces, see e.g. [119]. It needs to be established, however, to what extent metal surface models are valid also for organic adsorbates on metal oxides in view of the differences between the metal an the metal oxide band structures. The significance of the band gap, as well as of surface states in it, must in any case be considered [102]. 

Resonant processes dynamic solution of the Newns-Anderson Hamiltonian... 

In the next step, to analyze the resonant processes associated with charge exchange between He+ and He , we consider a spin-less Newns-Anderson Hamiltonian [18] where the level and the hopping terms Tis /a that have been neglected to calculate ElHe" "] and [He , are intioduced. This Hamiltonian reads... 

RESONANT PROCESSES DYNAMIC SOLUTION OF THE NEWNS-ANDERSON HAMILTONIAN... 

The physics community has developed a theoretical description of the surface chemical bond, which borrows from scattering theory [13, 14). The Newns-Anderson description of the surface chemical bond is that of a scattering resonance of colliding conduction electrons [15, 16). These theories have been essential for the development of a detailed understanding of the compromise between localization of electrons in a surface bond versus delocahzation of the valence electrons in the metal. 

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