Intramolecular vibrational energy redistribution and the quantum ergodicity transition: a phase space perspective

Abstract

The onset of facile intramolecular vibrational energy flow can be related to features in the connected network of anharmonic resonances in the classical phase space.

Machine learning classification of disrotatory IRC and conrotatory non-IRC trajectory motion for cyclopropyl radical ring opening

“…24,25,26 In many of these cases, quasiclassical direct dynamics trajectories descending from the transition state provide quantitative treatment of the nonstatistical selectivity, 27,28,29 capturing either non-minimum energy pathway/nonintrinsic reaction coordinate (non-IRC) motion or incomplete intramolecular vibrational redistribution (IVR). 30 While these organic reactions display dynamic selectivity, the origin of selectivity is generally not quantitatively analyzed due to the necessity of comparing hundreds or thousands of trajectories that each have a different starting vibrational-sampled atomic velocity configuration and structure as well as being propagated along a complex multi-dimensional energy landscape. Recently, there has been interest in developing qualitative protocols to predict dynamical reaction selectivity using only a few key points on an energy landscape or transition-state partial bond lengths, 31,32 and this type of approach was broadly introduced by Carpenter several years ago.…”

Arnold web and dynamical tunneling in a four-site Bose-Hubbard model

“…The origins for such behaviour has to do with the phenomenon of CAT [33,48,49] and RAT [32,49,50] in the vicinity of the multiplicity-2 resonance junctions and has been brought out clearly in earlier works [34,39,51] on different model systems. Near a resonance junction one expects a competition between transport due to local classical chaos and quantum transport dressed due to dynamical tunneling among near-degenerate states.…”

“…Therefore, combined with the fact that chaotic dynamics occurs in the vicinity of the junctions, there is an intriguing possibility of subtle competition between the classical and quantum transport. Note that recent studies [34,[37][38][39] in the molecular context have started to make progress on unraveling the influence of the junctions on both the classical and quantum transport. Thus, the multiple well trapped BECs provide a possible paradigm to experimentally identify these interesting higher dimensional transport and novel stability regimes.…”

“…In particular, a large body of theoretical work has focused on understanding and assigning the complicated quantum eigenstates from a classical-quantum correspondence viewpoint [42]. Such analysis are very important for understanding the phenomenon of intramolecular vibrational energy redistribution in molecules and ultimately lead to the formulation of accurate theories of reaction dynamics [39,[43][44][45].…”

Fundamental studies of vibrational resonance phenomena by multivalued resummation of the divergent Rayleigh–Schrödinger perturbation theory series: deciphering polyad structures of three H216O isotopologues

“…11 From a more general point of view, many studies were devoted to related physical phenomena: semiclassical dynamics of highly excited vibrational states, 5,8,17,22–29 bifurcations of periodic orbits, 5,28,29 algebraic methods in vibrational spectroscopy, 13,30,31 the polyad breaking, 32–34 the transformation of normal modes to local modes, 8,35–37 the dynamics of unimolecular chemical reactions, 4 as well as the intramolecular vibrational energy redistribution (IVR). 38…”