Cavity-Modified Fermi’s Golden Rule Rate Constants from Cavity-Free Inputs

Abstract

Equilibrium Fermi’s golden rule (FGR) rate constants are commonly used for modeling the kinetics of electronic energy and charge transfer processes in a wide range of molecular systems. The interaction between the electronic degrees of freedom and cavity modes can modify the coupling between electronic states when the molecular system is placed inside a cavity, and thereby alter the corresponding FGR rate constants. In this paper, we present a general-purpose framework for estimating the cavity-induced effect on equilibrium FGR rate constants. We show that cavity-modified equilibrium FGR rate constants can be estimated from inputs obtainable exclusively from a simulation of the cavity-free molecular system, thereby bypassing the need for an explicit simulation of the molecular system inside the cavity. The usefulness of this framework is demonstrated in the Marcus theory limit of equilibrium FGR, and general rules are derived for determining the optimal conditions for cavity-induced Marcus theory rate enhancement.