University of Edinburgh
Scientists are asking harder questions. Experiments have got tougher. The amount of information that can be gleaned, and therefore the interpretation of the results, is limited. So what do we do?
Computational chemistry has emerged in the last 10 years as an extremely important research tool to complement experiment. A model is built, and simulations are performed to mimic the experimental conditions. The model should reproduce what is already known from experiment, and crutially, provide the data that is missing. The result is that experiment and theory, together, provide the complete picture. The potential offered by simulation is so great that it now impacts on almost all areas of chemical research.
In my own research I apply ab initio calculations to study molecular materials. Specifically, I am interested in studying the very smallest atom - hydrogen. There are a number of reasons why this has thrown up some very interesting challenges. Firstly, because it is so small it is under represented in crystallographic experiments, meaning that we often don't know where they are. And yet, they are massively important, dictating, e.g. hydrogen bonding which can direct the packing of molecules in the crystal lattice, phase change behaviour, chemical reactivity etc.
We are also interested in studying materials with mobile H+ ions. This is the only ion that travels by making and breaking chemical bonds, and has the ability to tunnel through reaction barriers. This makes for challenging simulations! We have focussed our efforts in a number of applications, including catalysis and biochemical modelling. A particular highlight has been the ellucidation of the mechanism by which H+ ions can travel through membrane-bound proteins. This is the process that underpins many basic cell functions, including pH regulation, energy transfer and biosignalling, and has implications in several diseases including diabetes and Parkinson's.