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Related papers: The Dynamical Significance of Valley-Ridge Inflect…

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In this paper we compare the method of Lagrangian descriptors with the classical method of Poincare maps for revealing the phase space structure of two degree-of-freedom Hamiltonian systems. The comparison is carried out by considering the…

Chaotic Dynamics · Physics 2021-04-21 R. Crossley , M. Agaoglou , M. Katsanikas , S. Wiggins

In this paper we study an asymmetric valley-ridge inflection point (VRI) potential, whose energy surface (PES) features two sequential index-1 saddles (the upper and the lower), with one saddle having higher energy than the other and two…

Dynamical Systems · Mathematics 2022-04-20 Makrina Agaoglou , Matthaios Katsanikas , Stephen Wiggins

Chemical selectivity is a phenomenon displayed by potential energy surfaces (PES) that is relevant for many organic chemical reactions whose PES feature a valley-ridge inflection point (VRI) in the region between two sequential index-1…

Chemical Physics · Physics 2020-07-15 M. Agaoglou , V. J. Garcıa-Garrido , M. Katsanikas , S. Wiggins

We study reaction dynamics on a model potential energy surface exhibiting post-transition state bifurcation in the vicinity of a valley ridge inflection point. We compute fractional yields of products reached after the VRI region is…

Chemical Physics · Physics 2015-06-17 Peter Collins , Barry K. Carpenter , Gregory S. Ezra , Stephen Wiggins

Chemical selectivity, as quantified by a branching ratio, is a phenomenon relevant for many organic chemical reactions. It may be exhibited on a potential energy surface that features a valley-ridge inflection point in the region between…

Chemical Physics · Physics 2020-08-26 V. J. García-Garrido , M. Katsanikas , M. Agaoglou , S. Wiggins

We review recent results on the potential energy landscape (PES) of model liquids. The role of saddle-points in the PES in connecting dynamics to statics is investigated, confirming that a change between minima-dominated and…

Soft Condensed Matter · Physics 2012-11-26 Antonio Scala , Luca Angelani , Roberto Di Leonardo , Giancarlo Ruocco , Francesco Sciortino

We report a detailed study of the stationary points (zero-force points) of the potential energy surface (PES) of a model structural glassformer. We compare stationary points found with two different algorithms (eigenvector following and…

Disordered Systems and Neural Networks · Physics 2009-11-11 Tomas S. Grigera

In this study, we analyze how changes in the geometry of a potential energy surface in terms of depth and flatness can affect the reaction dynamics. We formulate depth and flatness in the context of one and two degree-of-freedom (DOF)…

Chemical Physics · Physics 2020-10-28 Wenyang Lyu , Shibabrat Naik , Stephen Wiggins

We study the phase space geometry associated with index 2 saddles of a potential energy surface and its influence on reaction dynamics for $n$ degree-of-freedom (DoF) Hamiltonian systems. For index 1 saddles of potential energy surfaces…

Chaotic Dynamics · Physics 2015-05-13 Gregory S. Ezra , Stephen Wiggins

In this article we present the influence of a Hamiltonian saddle-node bifurcation on the high-dimensional phase space structures that mediate reaction dynamics. To achieve this goal, we identify the phase space invariant manifolds using…

Chaotic Dynamics · Physics 2020-05-20 Víctor J. García-Garrido , Shibabrat Naik , Stephen Wiggins

We apply the minimum energy paths (MEPs) approach to study the helix unwinding transition in chiral nematic liquid crystals. A mechanism of the transition is determined by a MEP passing through a first order saddle point on the free energy…

Soft Condensed Matter · Physics 2020-01-08 Semen S. Tenishchev , Alexei D. Kiselev , Aleksei V. Ivanov , Valery M. Uzdin

Dynamical matching occurs in a variety of important organic chemical reactions. It is observed to be a result of a potential energy surface (PES) having specific geometric features. In particular, a region of relative flatness where…

Chaotic Dynamics · Physics 2020-02-26 M. Katsanikas , V. J. García-Garrido , S. Wiggins

Plenty of saddles on a multidimensional potential energy surface(PES) of two-dimensional microclusters, where atoms are interacting via Morse potential, are numerically located. The reaction paths emanating from the two types of the local…

Materials Science · Physics 2007-05-23 Yasushi Shimizu , Shin-ichi Sawada , Kensuke S. Ikeda

Selectivity is an important phenomenon in chemical reaction dynamics. This can be quantified by the branching ratio of the trajectories that visit one or the other wells to the total number of trajectories in a system with a potential with…

Chaotic Dynamics · Physics 2021-12-22 Douglas Haigh , Matthaios Katsanikas , Makrina Agaoglou , Stephen Wiggins

We investigate a classical lattice system with $N$ particles. The potential energy $V$ of the scalar displacements is chosen as a $\phi ^4$ on-site potential plus interactions. Its stationary points are solutions of a coupled set of…

Disordered Systems and Neural Networks · Physics 2009-11-11 Rolf Schilling

The stationary points of the potential energy function V are studied for the \phi^4 model on a two-dimensional square lattice with nearest-neighbor interactions. On the basis of analytical and numerical results, we explore the relation of…

Statistical Mechanics · Physics 2015-03-19 Michael Kastner , Dhagash Mehta

The most intriguing properties of non-Hermitian systems are found near the exceptional points (EPs) at which the Hamiltonian matrix becomes defective. Due to the complex topological structure of the energy Riemann surfaces close to an EP…

Classical Physics · Physics 2018-06-19 Xu-Lin Zhang , Shubo Wang , Bo Hou , C. T. Chan

In chemical reactions, trajectories typically turn from reactants to products when crossing a dividing surface close to the normally hyperbolic invariant manifold (NHIM) given by the intersection of the stable and unstable manifolds of a…

Chemical Physics · Physics 2020-11-10 Manuel Kuchelmeister , Johannes Reiff , Jörg Main , Rigoberto Hernandez

Many organic chemical reactions are governed by potential energy surfaces that have a region with the topographical features of a caldera. If the caldera has a symmetry then trajectories transiting the caldera region are observed to exhibit…

Chaotic Dynamics · Physics 2021-02-05 Y. Geng , M. Katsanikas , M. Agaoglou , S. Wiggins

By means of molecular dynamics simulations, we study the stationary points of the potential energy in a Lennard-Jones liquid, giving a purely geometric characterization of the energy landscape of the system. We find a linear relation…

Statistical Mechanics · Physics 2009-10-31 Kurt Broderix , Kamal K. Bhattacharya , Andrea Cavagna , Annette Zippelius , Irene Giardina
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