Ab-initio reconstruction of metastable-induced electron-emission spectra (MIES) for molecules

We developed a quantum-chemical approach for ab initio calculations of metastable-induced electron-emission spectra (MIES). In contrast to earlier work, our calculation method accounts for the anisotropy of the MIES spectra with respect to not only the direction of incidence of metastable helium but also to that of electron detection. Since we can freely choose both, incidence and detection direction in our simulation, our method is able to reconstruct MIES spectra which are dominated by Auger deexcitation for any experimental setups and orientation of the studied molecules. Here, we study the dependence of the MIES spectrum on the incidence and detection direction and other experimental parameters and compare the results for the case of adsorbed benzene with experimental data.