Barnes Update Applied in the Gauss−Newton Method: An Improved Algorithm to Locate Bond Breaking Points

A mechanochemical reaction is a reaction induced by mechanical energy. A general accepted model for this type of reactions consists in a first order perturbation on the associated potential energy surface (PES) of the unperturbed molecular system due to mechanical stress or pulling force. Within thi...

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Bibliographic Details
Authors: Bofill i Villà, Josep M., Valero Montero, Rosendo, Ribas Ariño, Jordi, Quapp, Wolfgang
Format: article
Status:Versión aceptada para publicación
Publication Date:2021
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/184952
Online Access:https://hdl.handle.net/2445/184952
Access Level:Open access
Keyword:Algorismes
Reaccions químiques
Algorithms
Chemical reactions
Description
Summary:A mechanochemical reaction is a reaction induced by mechanical energy. A general accepted model for this type of reactions consists in a first order perturbation on the associated potential energy surface (PES) of the unperturbed molecular system due to mechanical stress or pulling force. Within this theoretical framework, the so-called optimal barrier breakdown points or optimal bond breaking points (BBPs) are critical points of the unperturbed PES where the Hessian matrix has a zero eigenvector that coincides with the gradient vector. Optimal BBPs are 'catastrophe points' that are par- ticularly important because its associated gradient indicates how to optimally harness tensile forces to induce reactions by transforming a chemical reaction into a barrierless process. Building on a previous method based on a nonlinear least squares minimiza- tion to locate BBPs (Bofill et al., J. Chem. Phys. 2017, 147, 152710-10), we propose a new algorithm to locate BBPs of any molecular system based on the Gauss-Newton method combined with the Barnes update for the nonsymmetric Jacobian matrix, which is shown to be more appropriate than the Broyden update. The efficiency of the new method is demonstrated for a multidimensional model PES and two medium size molec- ular systems of interest in enzymatic catalysis and mechanochemistry.