title: Ring-Polymer Molecular Dynamics for the Prediction of Low-Temperature Rates: An Investigation of the C((1)D) + H2 Reaction.
abstract: Quantum mechanical calculations are important tools for predicting the rates of elementary reactions, particularly for those involving hydrogen and at low temperatures where quantum effects become increasingly important. These approaches are computationally expensive, however, particularly when applied to complex polyatomic systems or processes characterized by deep potential wells. While several approximate techniques exist, many of these have issues with reliability. The ring-polymer molecular dynamics method was recently proposed as an accurate and efficient alternative. Here, we test this technique at low temperatures (300-50 K) by analyzing the behavior of the barrierless C((1)D) + H2 reaction over the two lowest singlet potential energy surfaces. To validate the theory, rate coefficients were measured using a supersonic flow reactor down to 50 K. The experimental and theoretical rates are in excellent agreement, supporting the future application of this method for determining the kinetics and dynamics of a wide range of low-temperature reactions.
authors.affiliation: Institut des Sciences Moléculaires, Université de Bordeaux , F-33400 Talence, France.|CNRS, Institut des Sciences Moléculaires , F-33400 Talence, France.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Hickson
authors.affiliation: Institut des Sciences Moléculaires, Université de Bordeaux , F-33400 Talence, France.|CNRS, Institut des Sciences Moléculaires , F-33400 Talence, France.
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Loison
authors.affiliation: Department of Chemistry and Chemical Biology, University of New Mexico , Albuquerque, New Mexico 87131, United States.
authors.forename: Hua
authors.initials: H
authors.lastname: Guo
authors.affiliation: Computation-based Science and Technology Research Center, Cyprus Institute , 20 Kavafi Str., Nicosia 2121, Cyprus.|Department of Chemical Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States.
authors.forename: Yury V
authors.initials: YV
authors.lastname: Suleimanov
keywords: dynamics; kinetics; low-temperature reactions; ring-polymer molecular dynamics; suspersonic flow reactor