Analyzing intramolecular dynamics by Fast Lyapunov Indicators

TL;DR

This paper uses the Fast Lyapunov Indicator method to analyze the intramolecular dynamics of excited OCS molecules, revealing the transition from regular to chaotic behavior near dissociation energy.

Contribution

It introduces a combined stability and periodic orbit analysis to characterize dynamical regimes in molecular phase space.

Findings

Identification of regular and chaotic regions in phase space

Discovery of elliptic periodic orbits in regular regions

Detection of hyperbolic orbits associated with chaos

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.