SURPRISES: when ab initio meets statistics in extended systems

摘要: The surface photoelectron and inner shell electron spectroscopy (SURPRISES) program suite performs ab initio calculations of photoionization non-radiative decay spectra in nanoclusters solid state systems by using a space-energy similarity procedure to reproduce the band-like part spectra. This approach provides an extension Fano resonant multichannel scattering theory dealing with complexity arising from condensed matter at computational cost comparable that molecules. bottleneck is size Hilbert space where wavefunctions are expanded increase number final states comparison atoms In particular, diagonalization interchannel interaction take into account correlation between double ion escaping impracticable when hole delocalization on valence bands electronic excitations included model. To overcome this problem SURPRISES uses 'space-energy similarity' approach, which allows spreading Auger probability over without tuning semi-empirical parameters. Furthermore, completely new feature landscape processes represented including energy loss through statistical approach. Using calculated lineshape as source, Monte Carlo routine simulates effect inelastic losses original lineshape. process, computed spectrum can be directly compared acquired experimental spectra, thus avoiding background subtraction, not free uncertainty. exploit symmetry system under investigation reduce calculation scaling may compute photoemission angular distribution patterns for electrons emitted resonance-affected processes. paper, we present general methods, techniques numerical tests applied Si K–LL O different SiO2 nanoclusters.