To show the convenience brought by DMFF, we give a proof-of-concept example, in which a new water model 34 is implemented. This water model is based on a multipolar polarizable potential, which is quite similar to AMOEBA and MPID. We can then interface it with MD packages such as i-PI 35 to perform MD simulations, the results of which are shown in Figure . In the NVE simulation, the energy is well conserved within 0.02% of precision, verifying the smoothness of the potential and the correctness of the force evaluation. And the RDFs from the NVT path-integral MD simulation are also shown, demonstrating the capability of DMFF in bulk simulations. DMFF allows the developers to really focus on the part they are developing (i.e., the charge model), not concerning themselves with reinventing the wheel (i.e., the multipolar PME kernel) every time.