Chi Mak at the University of Southern California is supported by a grant from the Theoretical and Computational Chemistry Program to continue his research involving path integral simulations of condensed-phase quantum dynamics. The research has two major goals: 1) to understand the influence of the environment on the dynamics of tunneling systems such as those in electron transfer reactions; and 2) to develop new simulation techniques to accomplish this goal. Two models have thus far been developed by Mak: 1) a multilevel blocking (MLB) algorithm which works with models having several explicit degrees of freedom, and 2) a chromostochastic quantum dynamics (CSQD) method that works with models in which the environment is represented by an infinite collection of simple degrees of freedom. Mak will further develop these ideas and apply them to new systems, and also develop a new hybrid method to treat models outside the reach of either of the other two methods.
Electron transfer reactions are an important class of chemical reactions with particular relevance in chemistry and biology. In these reactions the electron's ability to tunnel from the donor to the acceptor is heavily influenced by its surroundings. Despite the success of Marcus theory, many questions, especially those related to the quantal features of electron tunneling dynamics, still remain. Mak's research will help to elucidate these important contributions, and further our understanding of this important class of chemical reactions.
