Dynamics on the Double Morse Potential: A Paradigm for Roaming Reactions with no Saddle Points

TL;DR

This paper investigates a two-dimensional Hamiltonian system with a double Morse potential, revealing how roaming reactions occur without saddle points and highlighting the role of flat regions in molecular transport.

Contribution

It introduces a novel model with a flat potential region and analyzes its dynamical behavior, shedding light on roaming reaction mechanisms in chemistry.

Findings

Transport occurs via roaming mechanisms in flat regions

The system exhibits dynamics similar to real roaming reactions

The model demonstrates reaction pathways without saddle points

Abstract

In this paper we analyze a two degree of freedom Hamiltonian system constructed from two planar Morse potentials. The resulting potential energy surface has two potential wells surrounded by an unbounded flat region containing no critical points. In addition, the model has an index one saddle between the potential wells. We study the dynamical mechanisms underlying transport between the two potential wells, with emphasis on the role of the flat region surrounding the wells. The model allows us to probe many of the features of the roaming mechanism whose reaction dynamics are of current interest in the chemistry community.