Hence, although we have outlined our roadmap to future improvements, a natural question is: where can the QUBE protein force field be used now (especially given the higher cost of parameterization compared to transferable force fields)? Importantly, it has been shown previously that the use of system-specific force field charges leads to improvements in binding energetics of small molecules, and reproduction of the QM electrostatic potential for both small molecules 27 and proteins. Therefore, although simulated protein backbone dynamics is an important test, we envisage the QUBE small molecule and protein force field being particularly important for the study of intermolecular interactions in the condensed phase.