Simple renormalization schemes for multiple scattering series expansions.

A number of renormalization schemes for improving the convergence of multiple scattering series expansions are investigated. Numerical tests on a small Cu(111) cluster demonstrate their effectiveness, for example increasing the rate of convergence by up to a factor 2 or by transforming a divergent series into a convergent one. These techniques can greatly facilitate multiple scattering calculations, especially for spectroscopies such as photoelectron diffraction, Auger electron diffraction, low energy electron diffraction , where an electron propagates with a kinetic energy of hundreds of eV in a cluster of hundreds of atoms.

Low energy electron and positron impact differential cross sections for the ionization of water molecules in the coplanar and perpendicular kinematics.

We report here triply differential cross sections (TDCSs) for 81 eV electron and positron-impact ionization of the combined (1b + 3a) orbitals of the water molecule by using the second-order distorted wave Born approximation (DWBA2) for ejection electron and positron energies of 5 eV and 10 eV and different momentum transfer conditions. The electron-impact TDCS will be compared with the experimental data measured by Ren et al. [Phys.

Layer-resolved study of Mg atom incorporation at the MgO/Ag(001) buried interface.

By combining x-ray excited Auger electron diffraction experiments and multiple scattering calculations we reveal a layer-resolved shift for the Mg KL23L23 Auger transition in MgO ultrathin films (4-6 Å) on Ag(001). This resolution is exploited to demonstrate the possibility of controlling Mg atom incorporation at the MgO/Ag(001) interface by exposing the MgO films to a Mg flux. A substantial reduction of the MgO/Ag(001) work function is observed during the exposition phase and reflects both band-offset variations at the interface and band bending effects in the oxide film.

Correlation expansion: a powerful alternative multiple scattering calculation method.

We introduce a powerful alternative expansion method to perform multiple scattering calculations. In contrast to standard MS series expansion, where the scattering contributions are grouped in terms of scattering order and may diverge in the low energy region, this expansion, called correlation expansion, partitions the scattering process into contributions from different small atom groups and converges at all energies. It converges faster than MS series expansion when the latter is convergent.