Computational approaches to study adsorption in MOFs with unsaturated metal sites

Metal-organic frameworks (MOFs) with coordinatively unsaturated sites (CUS) offer interesting possibilities for tuning the affinity of these materials towards certain adsorbates, potentially increasing their selectivity and storage capacity. From a modelling point of view, however, they pose a significant challenge due to the inability of conventional force-fields for dealing with these specific interactions. In this paper, we review recent developments in the application of quantum-mechanical (QM) methods and classical molecular simulations to understand and predict adsorption in MOFs with CUS. We find that hybrid approaches that incorporate QM-based information into classical models are able to provide dramatically improved adsorption predictions relative to conventional force-fields, while yielding a realistic description of the adsorption mechanism in these materials.