Abstract

Over the past decades molecular simulation has become an increasingly important tool in predicting and interpreting chemical processes. Inherent in these simulations is the assumption that the nuclei behave classically. However, for processes involving light particles such as hydrogen the quantum mechanical nature of the particles can dramatically alter their structure and dynamics. In this talk I will discuss systems ranging from the geochemically important fractionation of hydrogen isotopes between liquid water and its vapor to the biologically relevant proton delocalization in enzyme active sites where we have shown that the inclusion of such effects is essential to obtain the correct behavior. I will also discuss our recent progress in developing approaches to treat nuclear quantum mechanical fluctuations in condensed phase systems and to calculate isotope effects at a cost barely more than the a corresponding classical simulation. These advances allow us to investigate, in unprecedented detail, chemical systems where the inclusion of quantum mechanical effects is essential to obtain the correct result.