The article discusses the impact of different methods for calculating partial charges on the thermodynamic properties of adsorption in metal-organic frameworks (MOFs). Partial charges are artificial values assigned to atoms in classical molecular simulations to account for electrostatic interactions, but their calculation method can significantly affect simulation results.
Researchers at NIST compared various partial charge calculation schemes using density functional theory and popular MOFs like ZIF-8 and IRMOFs. They found that the computed adsorption isotherms and isosteric enthalpies of adsorption for light gases like CO₂ were highly dependent on the chosen charge calculation method.
The study highlights the importance of carefully selecting partial charge schemes in molecular simulations of MOFs, as different methods can lead to significantly different thermodynamic properties. While NIST provides high-quality quantum mechanical and simulation data, users are advised to exercise sound scientific judgment when selecting and applying these methods.
Keywords: partial charges, quantum-mechanical, density functional theory, Molecular Dynamics, Coulomb energy
