Ala-Nissila_1.4962167.pdf (507.61 kB)
Efficient dynamical correction of the transition state theory rate estimate for a flat energy barrier
journal contribution
posted on 2018-01-19, 13:29 authored by Harri Mokkonen, Tapio Ala-NissilaTapio Ala-Nissila, Hannes Jonsson© 2016 Author(s).The recrossing correction to the transition state theory estimate of a thermal rate can be difficult to calculate when the energy barrier is flat. This problem arises, for example, in polymer escape if the polymer is long enough to stretch between the initial and final state energy wells while the polymer beads undergo diffusive motion back and forth over the barrier. We present an efficient method for evaluating the correction factor by constructing a sequence of hyperplanes starting at the transition state and calculating the probability that the system advances from one hyperplane to another towards the product. This is analogous to what is done in forward flux sampling except that there the hyperplane sequence starts at the initial state. The method is applied to the escape of polymers with up to 64 beads from a potential well. For high temperature, the results are compared with direct Langevin dynamics simulations as well as forward flux sampling and excellent agreement between the three rate estimates is found. The use of a sequence of hyperplanes in the evaluation of the recrossing correction speeds up the calculation by an order of magnitude as compared with the traditional approach. As the temperature is lowered, the direct Langevin dynamics simulations as well as the forward flux simulations become computationally too demanding, while the harmonic transition state theory estimate corrected for recrossings can be calculated without significant increase in the computational effort.
Funding
This work was supported by the Academy of Finland through the FiDiPro program (H.J. and H.M., Grant No. 263294) and the COMP CoE (T. A-N., Grants Nos. 251748 and 284621).
History
School
- Science
Department
- Mathematical Sciences
Published in
Journal of Chemical PhysicsVolume
145Issue
9Citation
MOKKONEN, H., AL-NISSILA, T. and JONSSON, H., 2016. Efficient dynamical correction of the transition state theory rate estimate for a flat energy barrier. Journal of Chemical Physics, 145 : 094901.Publisher
© the Authors. Published by AIP PublishingVersion
- VoR (Version of Record)
Acceptance date
2016-08-01Publication date
2016Notes
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in MOKKONEN, H., AL-NISSILA, T. and JONSSON, H., 2016. Efficient dynamical correction of the transition state theory rate estimate for a flat energy barrier. Journal of Chemical Physics, 145 : 094901 and may be found at https://doi.org/10.1063/1.4962167ISSN
0021-9606Publisher version
Language
- en