Non-adiabatic dynamics combining Ehrenfest, decoherence, and multiscale approaches applied to ionic rare-gas clusters photodissociation, post-ionization fragmentation, and collisions

Publication date: Available online 4 March 2019Source: Computational and Theoretical ChemistryAuthor(s): René Kalus, Ivan Janeček, Florent Xavier GadéaAbstractMethodological approaches for realistic modeling of non-adiabatic processes are reviewed and selected applications are discussed. The methods are based on a hybrid approach with heavy atomic nuclei treated classically and light electrons described quantum mechanically. The core of the methodology consists in Ehrenfest’s mean-field approach enhanced by a model inclusion of quantum decoherence. Approximate treatment of long-time evolutions is also proposed for the cases where direct dynamical calculations become computationally impracticable. Specific applications to ionic clusters of rare gases, based on effective, low-dimensional Hamiltonians built within the diatomics-in-molecules methodology, prove the strengths and applicability of the developed methods in various fields like photodissociation, post-ionization fragmentation, and collisions.Graphical abstractSequential fragmentation of electronically highly excited Kr7+ ion upon electron-impact ionization of its neutral precursor (Kr7).

Source: Computational and Theoretical Chemistry - March 5, 2019 Category: Chemistry Source Type: research