[Colloquium] Computation Institute Presentation: From Charge Transfer to Coupled Charge Transport: A Multiscale Approach for Complex Systems

[Katie Casey]

Computation Institute Presentation

Speaker: Jessica M.J. Swanson, Ph.D, Center for Biophysical Modeling &  
Simulation, University of Utah, Department of Chemistry
Host: Ian Foster
Date: November 10, 2009
Time: 1:30 PM - 2:30 PM
Location: The University of Chicago, Searle Chemistry Lab, Rm 240a,  
5735 S. Ellis Ave.

Title: From Charge Transfer to Coupled Charge Transport: A Multiscale  
Approach for Complex Systems

Abstract: The coupled phenomena of electron transfer; proton  
transport, and redox reactions play a central role in most areas of  
energy production and conversion, from biomolecular energy  
transduction and natural water splitting mechanisms to fuel cells and  
biomimetic platforms for artificial photosynthesis and photocatalysis.  
As a first step, the role of charge transfer in the structure and  
dynamics of the hydrated proton will be characterized with an ab  
initio energy decomposition analysis. In conjunction with data from  
molecular dynamics simulations, it will be shown that the excess  
proton in bulk water exhibits very little resemblance to the classical  
hydronium ion. The significance of delocalization of the protonic  
charge defect in condensed phase and biomolecular systems will be  
discussed. Additionally, the future development of a novel multiscale  
computational approach, Coupled Charge Transport Molecular Dynamics  
(CCT-MD), will be described. This method will treat redox-coupled  
charge transport in complex biological, biomimetic, and synthetic  
molecular systems by simultaneously describing proton transport, which  
can occur over long distances and inherently involves electronic  
delocalization over many molecules, electron transfer (both adiabatic  
and non-adiabatic), and the dynamic motions of the aqueous and  
molecular systems. One aim of this methodology is to gain physical  
insights into the redox-leveling (i.e., charge-balancing) that enables  
multi-electron chemical reactions, such as water splitting,  
particularly those most relevant to the development of technologies  
that convert solar energy to storable fuels.