An improved path-integral method for golden-rule rates
| Autor: | Joseph E. Lawrence, David E. Manolopoulos |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Chemical Physics (physics.chem-ph)
010304 chemical physics Discretization Analytic continuation FOS: Physical sciences General Physics and Astronomy Spectral density 010402 general chemistry 01 natural sciences 0104 chemical sciences Transition state theory Physics - Chemical Physics 0103 physical sciences Path integral formulation Limit (mathematics) Statistical physics Physical and Theoretical Chemistry Quantum Mathematics Boson |
| DOI: | 10.1063/5.0022535 |
| Popis: | We present a simple method for the calculation of reaction rates in the Fermi golden-rule limit, which accurately captures the effects of tunnelling and zero-point energy. The method is based on a modification of the recently proposed golden-rule quantum transition state theory (GR-QTST) of Thapa, Fang and Richardson. While GR-QTST is not size consistent, leading to the possibility of unbounded errors in the rate, our modified method has no such issue and so can be reliably applied to condensed phase systems. Both methods involve path-integral sampling in a constrained ensemble; the two methods differ, however, in the choice of constraint functional. We demonstrate numerically that our modified method is as accurate as GR-QTST for the one-dimensional model considered by Thapa and coworkers. We then study a multi-dimensional spin-boson model, for which our method accurately predicts the true quantum rate, while GR-QTST breaks down with an increasing number of boson modes in the discretisation of the spectral density. Our method is able to accurately predict reaction rates in the Marcus inverted regime, without the need for the analytic continuation required by Wolynes theory. 13 pages, 4 figures |
| Databáze: | OpenAIRE |
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