The quality of molecular dynamics simulations strongly depends on the accuracy of the underlying force fields (FFs) that determine all intra- and intermolecular interactions of the system. Commonly, transferable FF parameters are determined based on a representative set of small molecules. However, such an approach sacrifices accuracy in favor of generality.
Here, an open-source and automated toolkit named Q-Force is presented, which augments these transferable FFs with molecule-specific parameters that are derived from quantum mechanical (QM) calculations. The molecular fragmentation procedure allows treatment of large molecules (less than 200 atoms) with low computational cost. The generated Q-Force FFs can be used at the same computational cost as transferable FFs, but with improved accuracy. Overall, the accuracy, user-friendliness, and minimal computational overhead of the Q-Force protocol, make it widely applicable for atomistic molecular dynamics simulations.
In this webinar, we will introduce the methodology and demonstrate the improved accuracy of Q-Force FFs on the vibrational properties and the potential energy surfaces of a selection of molecules. Additionally, we will discuss the interface of Q-Force with Q-Chem and demonstrate it with a hands-on example.