One way to test the hypothesis of motional narrowing is by applying IR lineshape theory. Accordingly, we used the parameters obtained from DFT to describe the C≡N transition dipole and frequency in terms of electrostatics and HB-geometry (Table and; eqs. 1, 2, 3, and 7) as a model to compute theoretical IR spectra from AMOEBA MD trajectories (referred to as a vibrational spectroscopic map, or "vsm"). Towards this goal, we first calculated the instantaneous C≡N transition dipoles and frequencies from MD simulations (performed with 20 fs time steps over 2 ns in aggregate) for oTN in water and methanol and F28oCNF, and we utilized the well-documented fluctuating frequency approximation (FFA) to calculate MD-based IR spectra. In FFA, a Fourier transformation of the auto-correlation of dipole and frequency fluctuations is used to calculate realistic lineshapes (eq. S3). Comparing the resulting computed IR spectra of oTN in water and methanol (Fig. and, respectively) with those from experiment, we observe a very good recapitulation. In water, the simulated spectra yield one symmetric band for the C≡N stretch, with a peak position (2232 cm -1 ) almost identical to the experimental value; in methanol, the FFA-based spectra show an asymmetric lineshape which occurs due to distinct H-bonded and non-H-bonded fractions absorbing at ~2233 and ~2228 cm -1 , respectively, which are again quite similar for experimental and computed spectra. Importantly, we can take the difference between the vsm frequencies and the previously determined frequencies due to the VSE alone (Fig. G, H; red lines in Fig. ) to determine apparent ∆𝜈̅ 𝐻𝐵,𝑣𝑠𝑚 values of 14.5 and 12.7 cm -1 for water and methanol, respectively, which deviate from the experimentally obtained values by < 0.7 cm -1 , an impressively close match. We used the same approach to calculate the IR spectrum and vsm blueshift for F28oCNF (Fig. ) and again obtain a good match for ∆𝜈̅ 𝐻𝐵 : comparing ∆𝜈̅ 𝐻𝐵,𝑜𝑏𝑠 /∆𝜈̅ 𝐻𝐵,𝑣𝑠𝑚 , we observe values of 11.8/13.6 cm -1 , i.e. a deviation of only 1.8 cm -1 .