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With the goal of accelerating the design and discovery of metal–organic frameworks (MOFs) for electronic, optoelectronic, and energy storage applications, we present a dataset of predicted electronic structure properties for thousands of MOFs carried out using multiple density functional approximations. Compared to more accurate hybrid functionals, we find that the widely used PBE generalized gradient approximation (GGA) functional severely underpredicts MOF band gaps in a largely systematic manner for semi-conductors and insulators without magnetic character. However, an even larger and less predictable disparity in the band gap prediction is present for MOFs with open-shell 3d transition metal cations. With regards to partial atomic charges, we find that different density functional approximations predict similar charges overall, although hybrid functionals tend to shift electron density away from the metal centers and onto the ligand environments compared to the GGA point of reference. Much more significant differences in partial atomic charges are observed when comparing different charge partitioning schemes. We conclude by using the dataset of computed MOF properties to train machine-learning models that can rapidly predict MOF band gaps for all four density functional approximations considered in this work, paving the way for future high-throughput screening studies. To encourage exploration and reuse of the theoretical calculations presented in this work, the curated data is made publicly available via an interactive and user-friendly web application on the Materials Project. [ABSTRACT FROM AUTHOR]

Through quantum‐chemical calculations, we investigate a family of metal–organic frameworks (MOFs) containing triazolate linkers, M2X2(BBTA) (M=metal, X=bridging anion, H2BBTA=1H,5H‐benzo(1,2‐d:4,5‐d′)bistriazole), for their ability to form terminal metal–oxo sites and subsequently activate the C−H bond of methane. By varying the metal and bridging anion in the framework, we show how to significantly tune the reactivity of this series of MOFs. The electronic structure of the metal–oxo active site is analyzed for each combination of metal and bridging ligand, and we find that spin density localized on the oxo ligand is not an inherent requirement for low C−H activation barriers. For the Mn‐ and Fe‐containing frameworks, a transition from ferromagnetic to antiferromagnetic coupling between the metal binding site and terminal oxo ligand during the C−H activation process can greatly reduce the kinetic barrier, a unique case of two‐state reactivity without a change in the net spin multiplicity. [ABSTRACT FROM AUTHOR]

A formalism is given for predicting reactivity of complex systems by combining electronic structure calculations with forcefield calculations within a transition state theory framework. The theory is employed in combination with the Fukui function to produce a simulation method capable of the ensemble sampling needed to examine sterically complex systems. An important linkage between reactivity information and energetic quantities is provided by introduction of the Fukui overlap integral. This spatial overlap integral measures the coincidence of electron donating regions on a nucleophile with electron accepting regions on the corresponding electrophilic reactant. We show that configurations with high values of this overlap integral tend to have lower density-functional theory energies. Thus, Fukui functions calculated once on single isolated reactants can be used to quickly estimate the reactivity of configurations generated using conventional forcefield-based simulations. The correlation between energies and high overlap integrals can also be used to identify initial guess configurations for transition state searches. However, in the present implementation, real transition states are not accessible because intramolecular geometry relaxation is not allowed. The proposed method is tested on electrophilic aromatic alkylation reactions. Simulation results successfully reproduce experimental substituent effects in a series of variously substituted aromatics. Especially encouraging is the ability of the simulations to predict steric effects in the reaction of toluene with a series of electrophiles of varying bulkiness. Further applications, previously inaccessible to simulation, are expected in systems where steric effects play a dominant role in determining reaction selectivity. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]