Aiming to provide a simple, empirical description for the anomalous HB blueshift of nitriles, we developed a model that describes HB effects on C≡N frequencies as the sum of the widely used VSE and an additional term, ∆𝜈̅ 𝐻𝐵 . This model describes ∆𝜈̅ 𝐻𝐵 in terms of HB geometry, i.e. HB heavy atom distance d(C≡N---Donor) and angle θ(C≡N---Donor). The physical basis for the distance and angle dependence are a combination of repulsive quadrupolar electrostatic interactions for head-on HBs and an interplay between Pauli repulsion and attractive multipolar interactions for side-on HBs, supporting previous interpretations of the blueshift's origin(s). These findings further expand on theoretical models that have aimed to understand H-bonding in terms of its quantum and/or classical mechanical nature, many of which have pointed towards a dominant (classical) electrostatic character; our study is in line with this latter view. We found an important third contributor to ∆𝜈̅ 𝐻𝐵 , the HB dynamics, also needs to be considered when using the model developed herein. ∆𝜈̅ 𝐻𝐵 values of rigid HBs with long residence times and minimal fluctuations are directly dependent on HB geometry; in contrast, nitrile IR bands for quickly fluctuating HBs experience motional narrowing, altering their lineshapes. Consequently, HB residence/exchange times should be considered when estimating HB geometry via ∆𝜈̅ 𝐻𝐵 . In closing, we emphasize that the nitrile model presented in eq. 7 works well for MOFs which have a different type of nitrile and different HB donors. This suggests that the model developed here is broadly applicable and can be used to characterize HBs for nitriles on diverse substrates, ranging from drugs to amino acids, and in diverse settings, ranging from electrodes to microdroplets to proteins.