are not performed at extreme temperature or pressures, we would not expect the geometry of neighboring atoms sites to change very much. Additionally, the potential generated by neighboring frozen densities (within the same molecule) should also remain remain relatively constant. As this potential will be equal and opposite to χ 0 determined above, we can therefore approximate the effects of electronegativity by simply ignoring all interactions with frozen atoms on the same nucleobase. If we were instead interested in changes in intramolecular induced dipole moments, for example when simulating systems measured by IR spectroscopy, then the neglect of this potential will play a more crucial role when determining ∆n. However, because we are more interested describing intermolecular interactions between nucleobases, for the purposes of establishing such a model, this approximation will suffice. To summarize, we group all linear terms into a single "potential" ϕ i that each ∆n i experiences when belonging to nucleobase A,