Scheme: Wolfson Research Merit Awards
Organisation: University of Oxford
Dates: Aug 2010-Jul 2015
Summary: My research is in theoretical chemistry. This is the field that Dirac started almost 100 years ago when he stated that:
"The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known, and the difficulty is only that the exact application of these laws leads to equations much too complicated to be soluble." (P.A.M. Dirac, Proc. Roy. Soc. A 123, 714, 1929).
Very little has changed since then. The laws to which Dirac refers are the laws of quantum mechanics, a wonderfully simple theory that provides the correct equation of motion for any problem a chemist could ever want to solve. The trouble is that it is still not possible to solve this equation exactly for any really interesting chemical problem, even on the fastest supercomputer in the world.
The only way to make any progress is to make an approximation. The work in my group focusses on the dynamics of chemical reactions, hydrogen bond dynamics in liquids, and the dynamics of coupled electron and nuclear spins. For the first two of these problems, we have developed an approximation based on imaginary time path integrals. These provide a practical way to calculate the exact thermodynamic and structural properties of even very complex systems, which is clearly a useful starting point for developing an approximation to their dynamics. To study spin systems, we have developed an approximation based on the classical vector model of angular momentum, which despite its simplicity is expected to become exact for many interesting observables as the number of coupled spins increases and the environment of the spin that is being interrogated becomes more complex. Applications of our methods range from studies of the hydrogen bond dynamics in liquid water to studies of the photochemical radical pair recombination reactions that are thought to be responsible for the compass sense of migratory birds.