Clathrates are crystalline materials consisting of a porous framework, built up by discrete molecules, that adsorb guest molecules in their pores . The framework acts as a host for the relatively weakly bound gaseous guests. In the absence of directional interactions between molecules, and disregarding lattice vibrations, the densest crystal structure of any given composition is the most stable one . Consequently, the empty host frameworks are generally unstable and clathrates are rare . Hydroquinone is one of the few widely known clathrateforming molecules . It has been extensively studied both experimentally and computationally. Hydroquinone easily forms clathrates with a large number of guests, including CO 2 under mild pressure . The hydroquinone H 2 clathrate was found experimentally only after a computational study predicted that such clathrates can form and that they may have more than one H 2 molecule in each pore , obviously of great interest for gas storage applications. The computational predictions have since been confirmed; the clathrate exhibits fast and reversible adsorption of hydrogen gas at room temperature and has double and triple occupancy of H 2 at elevated pressures . In addition, the demonstrated separation of ethane/methane and CO 2 /N 2 gas mixtures by hydroquinone clathrate is another example of a potential industrial application . Phenol and several para-substituted phenol derivatives are known to readily form clathrates with various gases at low temperatures, and because of their selective affinities for dif-ferent guests, they can be used for gas separation . Phenols with substitutions at the orthoand meta-positions are less prone to forming clathrates, but oand m-fluorophenol xenon clathrates have been described . Clathrates with a host framework of water molecules, commonly called clathrate hydrates, have been intensively studied because of the problems they cause during off-shore petroleum and natural gas extraction . The goal has then often been to avoid the formation of a water methane clathrate. More recently, additives that induce the formation of clathrate hydrates have been studied as a means to capture CO 2 from flue gas or for separating CO 2 from biogas pre-combustion . Computational studies of clathrates have mainly focused on the calculation of guest adsorption energies by traditional force field methods. The adsorption energy is calculated either from the static lattice energy , or with methods that consider the dynamics and generate a thermodynamic ensemble, such as molecular dynamics or Monte Carlo (MC) simulations . Lattice dynamics is an alternative to these methods, and can be performed with more accurate force fields , and at a moderate computational cost. Lattice dynamics studies of clathrates are rare, but Dang and Pettitt and Belosludov et al. performed lattice dynamics on hydroquinone clathrates with several guest molecules and compared the computationally obtained vibrational frequencies to experimental data. Conventional lattice dynamics does however rest on an assumption that the molecules are fixed in the crystal structures and only vibrate harmonically around their equilibrium positions, which is often an adequate approximation for close-packed molecular crystals , but probably less so for clathrates, as the guest molecules have a rattling motion in the cavities, rather than a vibrational one . The adsorption of gases in clathrates depend on both an enthalpic (static) binding energy, and an entropic part that depends on the guest molecules' motion, and how the presence of the guest affects the motion of the host framework. The ideal cavity size thus provides a balance of binding enthalpy (favouring a tight fit) and entropy (allowing the guest to move). Several researchers have noted this careful balance, and how the binding affinity of a guest in a host is related to the guest-to-cavity volume ratio . The guestto-cavity volume ratio, or the guest's packing coefficient, is hence an important property of clathrates. Maximal affinity occurs when the volume ratio is close to 55% , i.e. substantially less than close-packed. Crystal structure prediction (CSP) generates hundreds of hypothetical crystal structures in an 'energy landscape' . The main purpose of CSP has so far been about finding the most stable form and possibly a few metastable polymorphs, a few kJ/mol above the global minimum . Recently however, we have seen a change in the focus of some CSP studies, where a much larger part of the predicted crystal landscape was considered and structures with specific properties were targeted . Solvates, hydrates and clathrates have previously been the subject of crystal structure prediction studies, although far less often than single-component systems. CSP of multicomponent crystals are still rarely attempted because of the difficulty in efficiently sampling the vast space of all possible relative orientations and stoichiometric ratios between the different components, and predictions for multi-component crystals are often less successful than single-component crystals . There are often porous structures in the higher-energy regions of predicted crystal energy landscapes. These usually neglected structures may be empty host frameworks of inclusion compounds, solvates, or clathrates. A few computational studies have explored this possibility, and with notable success. Several such predictions have subsequently been experimentally confirmed . Cruz-Cabeza performed CSP on several clathrate forming molecules, including Dianin's compound , hydroquinone, p-cresol (50), and urea. The calculations successfully reproduced the host structures of several known clathrates, and allowed plausible candidate structures to be proposed for both the p-cresol clathrate and the rhombohedral inclusion compound of urea, whose crystal structures had previously not been fully determined . We have previously performed CSP calculations on oand m-fluorophenol (CSD: QAMWEH, QAMTUU), in order to determine the crystal structures of their xenon clathrates. By comparing predicted 129 Xe shielding tensors with experimentally observed chemical shifts and chemical shift anisotropies, we could propose plausible crystal structures for these clathrates . These successful studies show that predictions of clathrate structures in many cases can be effectively accomplished by performing CSP on the host molecule alone, and subsequently inserting guest molecules in predicted porous structures. The method relies on the assumption that the empty host framework is metastable and corresponds to a local lattice energy minimum, which is a reasonable assumption for clathrates with gaseous guests, but probably not for solvates or other multicomponent crystals. In this article, we present a screening for possible novel clathrates by computational methods. We combine CSP with calculations of the physical properties of a large number of predicted materials in an effort to rationally design functional materials for gas storage and separation. We describe lattice dynamics (LD) calculations and grand TTBI has four known polymorphs, and all are channel-type inclusion compounds . Resorcinol has three known close-packed polymorphs. It is not known to form clathrates, but based on its similarity to other phenol derivatives and its molecular shape, it is reasonable to speculate that it could form clathrates, and experimental searches have been carried out . CSP has previously been performed on resorcinol, using two different methods, in order to elucidate its peculiar helical crystal growth . Besides the greenhouse gases CO 2 and CH 4 , we include xenon as one of the guest molecules in this study. Xenon's polarizability makes it bind relatively strongly in clathrates, facilitating their formation, and its chemical shift tensor is extremely sensitive to the atom's immediate surroundings, allowing for precise solid state 129 Xe NMR experiments on clathrates. . In summary, we have performed LD and GCMC simulations on more than 200 predicted clathrates of resorcinol, oand mfluorophenol and TTBI with CO 2 , CH 4 and Xe. The study is a wide screening, aiming to identify possible materials suitable for gas separation and storage applications.