As a unique class of hybrid nanoporous materials, metalorganic frameworks (MOFs) have received tremendous interest over the last decade. The variation of metal oxides and the judicious choice of controllable organic linkers allow the pore size, volume and functionality to be tailored in a rational manner for designable architectures. MOFs thus provide a wealth of opportunities for engineering new membrane materials and have been considered as versatile candidates for many important potential applications. However, the number of MOFs synthesized to date is extremely large, thus experimental testing alone is economically expensive and practically formidable. With rapidly growing computational resources, molecular simulation has become an indispensable tool to characterize, screen, and design MOFs.