Analyzing intramolecular dynamics by fast Lyapunov indicators

Abstract

We report an analysis of intramolecular dynamics of the highly excited planar carbonyl sulfide (OCS) below and at the dissociation threshold by the Fast Lyapunov Indicator (FLI) method. By mapping out the variety of dynamical regimes in the phase space of this molecule, we obtain the degree of regularity of the system versus its energy. We combine this stability analysis with a periodic orbit search, which yields a family of elliptic periodic orbits in the regular part of phase space an a family of in-phase collinear hyperbolic orbits associated with the chaotic regime.

Dynamical tunnelling in molecules: quantum routes to energy flow

“…Significant efforts are needed to characterize the resonance web dynamically in order to have a clear understanding of how the specific features of the web influence the IVR. Recent works [60,61,62,63,67,68,220] are beginning to focus on extracting such details in systems with three or more degrees of freedom which promises to provide valuable insights into the classical and quantum mechanisms of IVR in polyatomic molecules. Perhaps such an understanding would allow one to locally perturb specific regions of the resonance web and hence ultimately lead to control over the classical and quantum dynamics.…”

“…Following the initial studies, which were perhaps ahead of their time, far fewer efforts were made for almost a decade but there has been a renewal of interest in the problem over the last few years with the NHIMs playing a crucial role. Armed with the understanding that the notion of partial barriers, chaos, and resonances are very different in N ≥ 3 fresh insights on transition state and RRKM theories, and hence IVR, are beginning to emerge [58,59,60,61,62,63,64,65,66,67,68,69].…”

Phase-space structures and ionization dynamics of the hydrogen atom in elliptically polarized microwaves

“…The main idea of the method is to study the evolution of the tangent vectors computed along a given trajectory of the system. This method has been applied to search for phase space structures in different types of problems: coupled standard maps [36], celestial mechanics problems [37], and vibrational dynamics of polyatomic molecules [14]. In this paper we apply this method to the atomic system.…”

“…The FLI method is independent of the dimensionality of the system. It provides pictures of global stability structures for any given subspace of the phase space of the system [14]. Besides, the method is robust because it is applicable even in regimes which cannot be studied by any other existing analytical methods.…”

Dynamical Bottlenecks to Intramolecular Energy Flow

“…t is time (in units of T0 = 0.063×10 −12 s) and ξP 1 are the frequency ridges (in units of T −1 0 ) in the time-frequency decomposition [14] of P1(t).potential V is fitted aswhere R 3 is the distance between O and S. The potential consists of Morse potentials V i for each diatomic pair and an interaction potential V I of the Sorbie-Murrell form [16]. A rich mixture of chaotic and regular dynamics is observed at energies close to dissociation [19]. The computations below were performed at 90% of the dissociation energy of the weaker bond.…”