On the short term, carbon capture is a viable solution to reduce human-induced CO2 emissions, which requires an energy efficient separation of CO2. Metal–organic frameworks (MOFs) may offer opportunities for carbon capture and other industrially relevant separations. Especially, MOFs with embedded open metal sites have been shown to be promising. Molecular simulation is a useful tool to predict the performance of MOFs even before the synthesis of the material. This reduces the experimental effort, and the selection process of the most suitable MOF for a particular application can be accelerated. To describe the interactions between open metal sites and guest molecules in molecular simulation is challenging. Polarizable force fields have potential to improve the description of such specific interactions. Previously, we tested the applicability of polarizable force fields for CO2 in M-MOF-74 by verifying the ability to reproduce experimental measurements. Here, we develop a predictive polarizable force field for CO2 in M-MOF-74 (M = Co, Fe,Mg, Mn, Ni, Zn) without the requirement of experimental data. Theforce field is derived from energies predicted from quantum mechanics.The procedure is easily transferable to other MOFs. To incorporateexplicit polarization, the induced dipole method is applied betweenthe framework and the guest molecule. Atomic polarizabilities areassigned according to the literature. Only the Lennard-Jones parametersof the open metal sites are parameterized to reproduce energies fromquantum mechanics. The created polarizable force field for CO2 in M-MOF-74 can describe the adsorption well and even betterthan that in our previous work.
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