It’s not such a bad approximation to organize my scientific research into the following strands:
- Applications and methods development in classical and quantum dynamics. Everything is made of up atoms and molecules, but they’re funny little things, existing in an interesting physical realm that incorporates elements of both classical and quantum mechanics. Thus, attempts to understand their dynamics (what they do, how they do it, and why they do it) require tools from both classical and quantum mechanics.
- Non-equilibrium statistical mechanics & energy flow. Nearly all chemical reactions involve some degree of energy flow. Typical bond strengths are on the order of tens of kcal mol-1, and surmounting the energy barriers associated with bond-breaking at ambient temperatures requires the localization of significant amounts of energy in a particular vibrational mode. In the gas phase, the models most commonly used for describing chemical change are canonical transition state theory (TST) and its microcanonical counterpart, Rice-Ramsperger-Kassel-Marcus (RRKM) theory. In solution phase, one of the most successful models for understanding energy flow is linear response theory, which arises from the fluctuation-dissipation theorem. TST, RRKM, and linear response theory are often adequate; however, they effectively assume that initial conditions are insignificant in descriptions of chemical reactivity. Increasingly sophisticated experimental and theoretical tools are providing significant insight into when and why these models break down – and the associated consequences for how we understand chemical reactivity.
- Applications and development of methods for formulating and solving the stochastic kinetic master equation. Chemistry is fundamental to understanding how nature behaves, and chemistry is about chemical reactions. However, rarely do natural systems involve simple isolated chemical reactions. Usually they involve extremely complicated networks of coupled reactions where every reaction directly or indirectly affects every other one. These sorts of kinetic networks occur everywhere in the underlying molecular fabric of nature. Understanding these networks requires some sophisticated machinery, and the stochastic master equation is one approach with which I’ve done quite a bit of work.
- Adiabatic & non-adiabatic Transition State Theory. One of the fundamental concepts that arises in quantum mechanics is the concept of a discreet state, as opposed to a Newtonian classical continuum. Lots of good chemical models are available for describing what molecules do on one particular electronic state, but the models are less reliable for describing what happens when molecules hop between states, and such processes are fundamental to understanding a variety of natural processes, from photosynthesis to atmospheric chemistry.
- Atmospheric Chemistry. The earth’s atmosphere is a massive low temperature chemical reactor where sunlight (not heat) provides much of the initial energy required to start chemical chain reactions. The atmosphere’s composition is important to life on earth, affecting the air that living organisms breath and influencing climate. Understanding atmospheric composition, behavior, and associated human impacts requires insight into the delicately balanced coupled chemical kinetic reaction networks which influence our atmosphere on both local, regional, and global scales. A significant part of my Ph.D. work was to design and utilize HIRAC – a highly instrumented chamber for investigating atmospheric photochemistry and kinetics.