Microcanonical and thermal instanton rate theory for chemical reactions at all temperatures

Richardson, Jeremy O.

Abstract

Semiclassical instanton theory is used to study the quantum effects of tunnelling and delocalization in molecular systems. An analysis of the approximations involved in the method is presented based on a recent first-principles derivation of instanton rate theory [J. Chem. Phys., 2016, 144, 114106]. It is known that the standard instanton method is unable to accurately compute thermal rates near the crossover temperature. The causes of this problem are identified and an improved method is proposed, whereby an instanton approximation to the microcanonical rate is defined which is integrated numerically to obtain a thermal rate at any temperature. No new computational algorithms are required, but only data analysis of a number of standard instanton calculations.

Citation

Richardson, J. O. (2016). Microcanonical and thermal instanton rate theory for chemical reactions at all temperatures. Faraday Discussions, 195, 49-67. https://doi.org/10.1039/c6fd00119j

• Journal Article Type: Article
• Acceptance Date: May 23, 2016
• Online Publication Date: May 23, 2016
• Publication Date: Dec 1, 2016
• Deposit Date: May 24, 2016
• Publicly Available Date: May 24, 2016
• Journal: Faraday Discussions
• Print ISSN: 1359-6640
• Electronic ISSN: 1364-5498
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 195
• Pages: 49-67
• DOI: https://doi.org/10.1039/c6fd00119j
• Public URL: https://durham-repository.worktribe.com/output/1404173