Excited-state diffusion-influenced reversible association–dissociation reaction: Brownian dynamics simulation in three dimensions

Abstract

Dynamic correlation effect in reversible diffusion-influenced reactions: Brownian dynamics simulation in three dimensionsExcited-state diffusion-influenced reversible reaction, A*ϩB C*, is investigated in three dimensions by suitably modifying the Brownian dynamics simulation algorithm of Edelstein and Agmon ͓J. Chem. Phys. 99, 5396 ͑1993͔͒ which requires the exact Green functions of the geminate system. The proposed simulation algorithm is based on using the mixed look-up tables. For the excited bound state, the unimolecular decay is coupled to the reactive movement and its trajectory can be calculated with the aid of the excited-state look-up table. On the other hand, the unimolecular decay of the excited unbound state is assumed to be independent of the reactive movement and its trajectory is calculated with the ground-state look-up table. The optimum size of the time step is found by fitting simulations performed for the geminate case to the analytic result. The simulation results with varying concentration of B particles as well as the ratio of unimolecular decay constants are in excellent agreement with the kinetic theoretical predictions of Kwac et al. ͓J. Chem. Phys. 114, 3883 ͑2001͔͒.

Excited‐State Reversible Geminate A*+B↔C*+D Reaction in Two Dimensions

“…The present work provides the complete theoretical solutions for the geminate reactions in two dimensions, which are routinely observable in experiments. When the reactant concentration is high and the effects of competitive reactions are non-negligible, we cannot obtain exact analytical solutions but the present solutions can be used to devise efficient many-body Brownian dynamics simulation algorithms [33][34][35][36][37][38] for numerically exact results in two dimensions.…”

Long-time kinetics of the excited-state association–dissociation reaction with different lifetimes

“…Using 'kinetic theory' [18], Kwac et al [21] suggested that the long-time behaviour of the excited-state reversible reaction is always purely exponential (except when k A = k C ). This has been tested using Brownian dynamics simulations [25]. However, the exponent of the decay was found only numerically.…”