Such a change may lead to the change of the molecular dipole, a phenomenon sometimes termed (intramolecular) polarization, and the change of the net charge of the water molecule due to the (intermolecular) charge transfer (CT). The effects of polarization and CT may In this work, we embrace the latter strategy by developing an improved and efficient DMS for existing, computationally efficient rigid non-polarizable water models, using the partial atomic charges predicted from machine learning (ML) trained against quantum chemical calculations. We take the TIP4P/2005 model, one of the best rigid non-polarizable water models, as an example to demonstrate our approach. Our DMS with the ML-based partial atomic charges not only significantly improves the prediction of the dielectric constant of liquid water from the MD trajectory using TIP4P/2005, but also reproduces the 200 cm -1 peak in the low-frequency IR spectrum of liquid water, which is completely missing in the computed spectrum from the TIP4P/2005 point charges. Our analysis suggests that within the framework of partial atomic charges, polarization accounts for the enhancement of the dielectric constant, whereas CT is predominantly responsible for the presence of the 200 cm -1 peak in the IR spectrum of liquid water. We also show that a proper amount of Hartree-Fock (HF) exchange in the density functional is critical to the balanced descriptions of polarization and CT in liquid water.