Zeolites are amongst some of the most important heterogeneous catalysts in use commercially today, combining acid-base catalysis due to the presence of Bronsted acid sites with shape selectivity resulting from the microporous environment [1]. Despite this, then is still a great deal of uncertainty concerning the mechanisms of many of the processes which are known to occur and the way in which the zeolite accelerates them. While much information has been obtained from experimental techniques, including infra-red spectroscopy and magic angle spinning NMR [2], there is presently a need for models and reaction pathways to aid in their interpretation Here theoretical methods are playing a major role in the field of microporous materials.