Dynamics of the O(3P) + CHD3(vCH = 0,1) reactions on an accurate ab initio potential energy surface

• Type of Material: Article
• Authors: Gábor Czakó, Eötvös University; Joel Bowman, Emory University
• Language: English
• Date: 2012-05-22
• Publisher: National Academy of Sciences
• Publication Version: Final Published Version
• Copyright Statement: © 2017 National Academy of Sciences.
• Final Published Version (URL): http://dx.doi.org/10.1073/pnas.1202307109
• Title of Journal or Parent Work: Proceedings of the National Academy of Sciences
• ISSN: 0027-8424
• Volume: 109
• Issue: 21
• Start Page: 7997
• End Page: 8001
• Grant/Funding Information: The work was funded by the National Science Foundation (CHE-0625237) (to G.C.); the Scientific Research Fund of Hungary (OTKA, NK83583) (to G.C.); and the European Union and the European Social Fund (TÁMOP-4.2.1/B-09/1/KMR-2010-0003) (to G.C.); and the Department of Energy (DE-FG02-97ER14782) (to J.M.B.).
• Keywords: benchmark ab initio data; state-to-state dynamics; reactive scattering computations; permutationally invariant potential energy surfaces; mode-specific dynamics
• Research Categories: Chemistry, General

Abstract

Recent experimental and theoretical studies on the dynamics of the reactions of methane with F and Cl atoms have modified our understanding of mode-selective chemical reactivity. The O + methane reaction is also an important candidate to extend our knowledge on the rules of reactivity. Here, we report a unique full-dimensional ab initio potential energy surface for the O(3P) + methane reaction, which opens the door for accurate dynamics calculations using this surface. Quasiclassical trajectory calculations of the angular and vibrational distributions for the ground state and CH stretching excited O + CHD3(v1 = 0,1) → OH + CD3 reactions are in excellent agreement with the experiment. Our theory confirms what was proposed experimentally: The mechanistic origin of the vibrational enhancement is that the CH-stretching excitation enlarges the reactive cone of acceptance.