The vibrational spectra of water's OH bond stretch, relevant to the spectral region of interest, was computed using the field mapping method. In this approach, the electric field is evaluated at each Hydrogen atom is computed and projected along the bond. The fre-quency of the OH bond stretch, ω, then undergoes a vibrational Stark shift from its vacuum value, ω 0 , due to this projected electric field, ε. In liquid water, this vibrational Stark shift can be fit to experimental Raman spectra or to electronic structure calculations and is well approximated by a linear fit of the form