Activationless and pseudoactivationless primary electron transfer in photosynthetic bacterial reaction centers

Abstract

A weak temperature dependence of the electron transfer (ET) rate, which is ubiquitous in ET processes in photosynthetic reaction centres, is expected when the nuclear potential surfaces cross in the energy range of the zero-point energy of the initial state. We introduce the concept of pseudoactivationless ET, which is explored using nonadiabatic theory. The activationless limit is adequate for exploring the gross, universal features of the temperature dependence of the primary charge separation in bacterial photosynthesis.