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Free keywords:
Rotational alignment; wave packet dynamics; photodesorption; LASER-INDUCED DESORPTION; SCHRODINGER-EQUATION; SURFACE PHOTOCHEMISTRY; QUANTUM DYNAMICS; SPECTRAL METHOD; DENSITY-MATRIX; Cr2O3(0001); POPULATION; MOLECULES; NEUTRALS
Abstract:
The influence of rovibrational preexcitation in the CO/Cr2O3(0 0 0 1)-system is studied theoretically using a three-dimensional quantum wave packet approach. We find that selectively excited hindered rotational levels of the adsorbate-substrate system influence the experimentally observed rotational alignment of the desorbing CO-molecule significantly. Pure vibrational preexcitation has less effect on the observables of interest. We predict only low surface temperature dependence of the rotational alignment and of the desorption yield. Our study is based on ab initio potential energy surfaces (PESs) for the electronic states involved and on a stochastic wave packet method.
