Simon Petrie is a Research Officer in the Computational Chemistry Group, he lectures in Practical Aspects of Computational Chemistry. His current research interests involve quantum chemical studies of (i) periodic trends in metal-metal bonding in polynuclear metal systems to quantify the electronic factors affecting metal-metal interactions. (ii) small molecule activation and cleavage in coordinatively unsaturated transition metal complexes capable of cleaving a variety of small molecules, including N2, NO, CO, CS and CN–. (iii) the structural and energetic dependence of the Mn4Ca cluster in Photosystem II on the oxidation states of the Mn ions, their magnetic coupling arrangements, and level of hydration.