Efficient transition path sampling for systems with multiple reaction pathways.

L Y Chen; P L Nash; N J M Horing

doi:10.1063/1.2013213

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Efficient transition path sampling for systems with multiple reaction pathways.

L Y Chen·P L Nash·N J M Horing

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Abstract

A new algorithm is developed for sampling transition paths and computing reaction rates. To illustrate the use of this method, we study a two-dimensional system that has two reaction pathways: one pathway is straight with a relatively high barrier and the other is roundabout with a lower barrier. The transition rate and the ratio between the numbers of the straight and roundabout transition paths are computed for a wide range of temperatures. Our study shows that the harmonic approximation for fluctuations about the steepest-descent paths is not valid even at relatively low temperatures and, furthermore, that factors related to entropy have to be determined by the global geometry of the potential-energy surface (rather than just the local curvatures alone) for complex reaction systems. It is reasonable to expect that this algorithm is also applicable to higher dimensional systems.

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Algorithms Chemistry, Physical Computer Simulation Diffusion Entropy Models, Chemical Models, Statistical Models, Theoretical Normal Distribution Temperature Thermodynamics Journal Article Research Support, N.I.H., Extramural Research Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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L Y Chen, P L Nash, N J M Horing. 2005-09-01. Efficient transition path sampling for systems with multiple reaction pathways.. https://doi.org/10.1063/1.2013213

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