Effect of the Intermolecular Excitation in the Vibrational Predissociation Dynamics of van der Waals Complexes and the Implications for Control

Abstract

The effect of intermolecular excitation on the vibrational predissociation lifetime is investigated systematically for different vdW complexes Rg-X2(B, v') (Rg = rare gas atom, X = halogen atom) by means of wave packet simulations. The lifetime as a function of intermolecular excitation displays a pattern of maxima and minima, with a similar shape for the different Rg-X2(B, v') complexes. The pattern is consistent with previous experimental findings involving lifetimes of intermolecular excitations in similar systems. The structure of the lifetime pattern is found to be determined by the shape of the resonance wave functions in the two van der Waals degrees of freedom, and more specifically by the magnitude of the overlap between the wave function and the coupling responsible for predissociation. Lifetime maxima and minima are associated with minima and maxima of this overlap, respectively. Implications for control of the complex lifetime are discussed.

Femtosecond predissociation dynamics of the methyl radical from the 3pz Rydberg state

“…A monotonic increase of the magnitude of C is what causes the decrease of t. Since both the magnitude and position of V coup are fixed, regardless of the initial vibrational excitation, only changes in the shape of c n 1 ,n 2 and w E=En 1 ,n 2 with increasing vibrational excitation and energy can cause an increase (decrease) of C(t). 38 Indeed, increasing the n 1 stretching excitation causes an increase of the spatial spreading of c n 1 ,n 2 toward larger R C-H distances. Similarly, the corresponding increase of the energy E = E n 1 ,n 2 causes also a larger delocalization of the continuum wave function w E=En 1 ,n 2 toward shorter R C-H distances.…”

Fragmentation of molecules by virtual photons from remote neighbors

“…The dissociation of systems containing rare gases has been widely studied. Examples are rare gas dimer and trimer ions, rare gas complexes with halogen molecules and with aromatics, see, e.g., [15][16][17] and references therein. The available photodissociation investigations essentially relate to excited electronic states because the cross sections at photon energies below those states are usually too small to be measured.…”

NeI2 Photofragmentation Dynamics Through Quasiclassical and Semiclassical Studies

“…These systems constitute a prototype of enormous importance for the understanding of intermolecular interactions, as well as for the investigation of vibrational and electronic coupling. [1][2][3][4][5][6][7][8][9][10] One of the methods for the study of such systems is the QCT (Quasi-Classical Trajectories), [11][12][13][14][15][16][17][18][19] which solves the classical equations of nuclear motion in the field described by a single PES (Potential Energy Surface), for a group of systems under given initial conditions. To do this, the coordinates and momenta are chosen randomly with the objective that the classical internal energy of the system matches with the desired quantum state.…”

“…Among the simplest systems, we find those formed by a noble gas (He, Ne, Ar …) and a dihalogen component (I 2 , Br 2 , Cl 2 , ICl, IBr …). These systems constitute a prototype of enormous importance for the understanding of intermolecular interactions, as well as for the investigation of vibrational and electronic coupling [1–10] …”