Exploring isomerization dynamics on a potential energy surface with an index-2 saddle using lagrangian descriptors

• Published in: Communications in nonlinear science & numerical simulation 2020-10, Vol.89, p.105331, Article 105331
• Main Authors: García-Garrido, Víctor J., Agaoglou, Makrina, Wiggins, Stephen
• Format: Article
• Language: English
• Subjects: Chemical reaction dynamics; Dynamical systems; Geometry; Index-2 saddles; Initial conditions; Isomerization; Lagrangian descriptors; Nonlinear equations; Nonlinear systems; Phase space structure; Potential energy; Symmetry
• ISSN: 1007-5704; 1878-7274
• DOI: 10.1016/j.cnsns.2020.105331

•Analysis of the phase space structures associated to index-2 saddles with Lagrangian descriptors.•Detection of reactivity regions for which the system undergoes distinct isomerization routes.•Influence of coupling and symmetry-breaking perturbations on the system’s dynamical behavior. In this paper we explore the phase space structures governing isomerization dynamics on a potential energy surface with four wells and an index-2 saddle. For this model, we analyze the influence that coupling both degrees of freedom of the system and breaking the symmetry of the problem have on the geometrical template of phase space structures that characterizes reaction. To achieve this goal we apply the method of Lagrangian descriptors, a technique with the capability of unveiling the key invariant manifolds that determine transport processes in nonlinear dynamical systems. This approach reveals with extraordinary detail the intricate geometry of the isomerization routes interconnecting the different potential wells, and provides us with valuable information to distinguish between initial conditions that undergo sequential and concerted isomerization.