{"title":"Ring-polymer instanton theory","authors":"Jeremy O. Richardson","doi":"10.1080/0144235X.2018.1472353","DOIUrl":null,"url":null,"abstract":"Abstract Instanton theory provides a simple description of a quantum tunnelling process in terms of an optimal tunnelling pathway. The theory is rigorously based on quantum mechanics principles and is derived from a semiclassical approximation to the path-integral formulation. In multidimensional systems, the optimal tunnelling pathway is generally different from the minimum-energy pathway and is seen to ‘cut the corner’ around the transition state. A ring-polymer formulation of instanton theory leads to a practical computational method for applying the theory to describe, simulate and predict quantum tunnelling effects in complex molecular systems. It can be used to compute either the rate of a tunnelling process leading to a chemical reaction or the tunnelling splitting pattern of a molecular cluster. In this review, we introduce a unification of the theory’s derivation and discuss recent improvements to the numerical implementation.","PeriodicalId":54932,"journal":{"name":"International Reviews in Physical Chemistry","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2018-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"51","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Reviews in Physical Chemistry","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1080/0144235X.2018.1472353","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 51
Abstract
Abstract Instanton theory provides a simple description of a quantum tunnelling process in terms of an optimal tunnelling pathway. The theory is rigorously based on quantum mechanics principles and is derived from a semiclassical approximation to the path-integral formulation. In multidimensional systems, the optimal tunnelling pathway is generally different from the minimum-energy pathway and is seen to ‘cut the corner’ around the transition state. A ring-polymer formulation of instanton theory leads to a practical computational method for applying the theory to describe, simulate and predict quantum tunnelling effects in complex molecular systems. It can be used to compute either the rate of a tunnelling process leading to a chemical reaction or the tunnelling splitting pattern of a molecular cluster. In this review, we introduce a unification of the theory’s derivation and discuss recent improvements to the numerical implementation.
期刊介绍:
International Reviews in Physical Chemistry publishes review articles describing frontier research areas in physical chemistry. Internationally renowned scientists describe their own research in the wider context of the field. The articles are of interest not only to specialists but also to those wishing to read general and authoritative accounts of recent developments in physical chemistry, chemical physics and theoretical chemistry. The journal appeals to research workers, lecturers and research students alike.