Accurate quantum dynamics of a combustion reaction: Thermal rate constants of O(3P)+CH4(X 1A1)→OH(X 2Π)+CH3(X 2A2″)

Abstract

A quantum dynamics study of a polyatomic combustion reaction accurately considering all its internal degrees of freedom is presented. The thermal rate constants for the O(3P)+CH4(X 1A1)→OH(X 2Π)+CH3(X 2A2″) reaction is calculated and compared to experimental and approximate theoretical results. Good agreement with experiment is found and the reliability of some of the approximate approaches is confirmed.

Communication: Imaging the effects of the antisymmetric-stretching excitation in the O(3P) + CH4(v3 = 1) reaction

“…Its thermal kinetics has been extensively studied both experimentally 2 and theoretically. [3][4][5][6][7][8][9][10][11][12] There are also a few experimental studies of the ground-state reaction dynamics, [13][14][15][16][17] from which the key observations can be summarized as follows. (1) The OH rotational distribution is relatively cold.…”

Communications: A rigorous transition state based approach to state-specific reaction dynamics: Full-dimensional calculations for H+CH4→H2+CH3

“…Rigorous full-dimensional quantum dynamics calculations for X +CH 4 reactions have been restricted to the calculation of thermal rate constants and cumulative reaction probabilities for J =0. [4][5][6][7][8][9][10][11][12] Quantum mechanical studies of state-resolved observables have been restricted to reduced-dimensional calculations. The most elaborate studies could include six to seven degrees of freedom explicitly.…”

The reaction rate for dissociative adsorption of N2 on stepped Ru(0001): Six-dimensional quantum calculations

“…This was also found in previous calculations for gas-phase systems. 22,23 The rotational and vibrational partition functions of N 2 have been computed within the rigid rotor and the harmonic oscillator approximations, respectively. Relevant PES data obtained from DFT calculations are given in Table IV.…”

“…As a solution to this problem one can use a harmonic progression model to enhance the convergence. 23 Assuming that N i ͑E͒ has been computed for i =1,n, the contributions N i ͑E͒ i = n +1...ϱ are estimated using a harmonic progression. The best estimate of the rate constant based on the data for the n lowest vibrational states of the activated complex then reads 23…”

“…The combination of the flux correlation approach with the multiconfiguration time-dependent Hartree ͑MCTDH͒ scheme for efficient multidimensional wave-packet propagation made it possible to study the quantum dynamics of 12-dimensional systems. [20][21][22][23][24][25] The previous studies show that quantum effects are significant in reactions where hydrogen atoms are transferred. At room temperature the tunneling effect often increases the reaction rate by one order of magnitude.…”