on ionization pattern. A typical example here is the case of resonant ionization occurring when the laser frequency comes close to an eigenfrequency of the system [@Cal00].

Equally important in energetic irradiation processes is electron transport, particularly electron emission. As typical examples, one can cite the many studies on irradiation of clusters by short and intense laser pulses [@Fen10], providing invaluable information especially through energy (Photo-Electron Spectra, PES [@Cam00]) and, more recently, angle-resolved [@Bar09] distributions of emitted electrons (Photoelectron Angular Distributions, PAD). Electron emission can also change the resonant ionization conditions in the course of time evolution which, in turn, influences back again the optical response, making the whole scenario extremely rich [@Fen10]. Secondary electrons in DNA damage [@Bou00] also provide a remarkable example where a microscopic understanding of irradiation damage in biological systems will only be achieved when including such complex non-linear electronic effects. A deeper understanding of the underlying mechanisms is highly desirable, as this example is of great practical interest, especially in relation to oncology [@Gar12].

The analysis and understanding of electronic emission from a finite system is thus a key issue in a wide range of physical, chemical and biological processes. Electrons are usually the first 