Schrodinger equation Nonlinear equations 10 Mathematical models 8 Ultrashort pulses 8 Correlation methods 6 Grazing incidence 6 Ionization 6 Metal surfaces 6 Time dependent Schrodinger equation 6 Approximation theory 4 Band structure 4 Band-structure-based models 4 Condensed matter physics 4 Contracted schrodinger equation 4 Correlation matrix 4 Distorted waves 4 Electron transitions 4 Electronic correlation effects 4 Emission spectroscopy 4 Helium 4 Ions 4 Numerical solution 4 Photo-electron emission 4 Photoelectron spectroscopy 4 Photoelectrons 4 Photoionization 4 Photons 4 Reduced density matrix 4 Structure-based 4 Activation energy 2