Our calculations and analysis attribute the origin of the hydrogen-bond stretch peak at 200 cm -1 to intermolecular CT within the framework of partial atomic charges, consistent with the conclusions from some previous AIMD simulations and some water models that incorporate CT. However, some polarizable models without CT explicitly included, e.g., the iAMOEBA model, are also able to reproduce this peak, albeit often with a smaller intensity than the experimental spectrum. These seemingly contradictory conclusions may not be surprising in that the concepts of intramolecular polarization and intermolecular CT depend on how the charges or dipoles are assigned to each molecule. Our comprehensive survey of different models and AIMD simulations in Sections 4 and 5 of the SI suggests that the substantial charge redistribution between the two hydrogen-bonded water molecules, responsible for the 200 cm -1 peak in the IR spectrum, can be captured in modeling by the explicit inclusion of intermolecular CT in the DMS of water, the effective incorporation of the CT effects into induced molecular dipole (or multipoles), or the use of an explicit many-body DMS. In our model with the DMS described solely by atom-centered partial atomic charges, the intermolecular CT is essential in generating the 200 cm -1 peak.