Ring-Polymer Molecular Dynamics for the Prediction of Low-Temperature Rates: An Investigation of the C(<sup>1</sup>D) + H<sub>2</sub> Reaction Kevin M. Hickson Jean-Christophe Loison Hua Guo Yury V. Suleimanov 10.1021/acs.jpclett.5b02060.s001 https://acs.figshare.com/articles/journal_contribution/Ring_Polymer_Molecular_Dynamics_for_the_Prediction_of_Low_Temperature_Rates_An_Investigation_of_the_C_sup_1_sup_D_H_sub_2_sub_Reaction/2055198 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(<sup>1</sup>D) + H<sub>2</sub> 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. 2015-12-17 10:31:13 dynamics method polyatomic systems future application quantum effects rate coefficients technique flow reactor H 2 reaction 50 K H 2 ReactionQuantum energy surfaces