Beyond the Status Quo: Density Functional Tight Binding and Neural Network Potentials as a Versatile Simulation Strategy to Characterize Host-Guest Interactions in Metal- and Covalent Organic Frameworks

In recent years,research focused on synthesis, characterization,and application of metal-organic frameworks (MOFs) has attractedincreased interest, from both an experimental as well as a theoreticalperspective. Self-consistent charge density functional tight binding(SCC DFTB) in conjunction with a suitable constrained molecular dynamics(MD) simulation protocol provides a versatile and flexible platformfor the study of pristine MOFs as well as guest@MOF systems. Althoughbeing a semi-empirical quantum mechanical method, SCC DFTB inherentlyaccounts for polarization and many-body contributions, which may becomea limiting factor in purely force field-based simulation studies.A number of examples such as CO2, indigo, and drug moleculesembedded in various MOF hosts are discussed to highlight the capabilitiesof the presented simulation approach. Furthermore, a promising extensionof the outlined simulation strategy toward the treatment of covalentorganic frameworks utilizing state-of-the-art neural network potentialsproviding a description at DFT accuracy and force field cost is outlined.