The generalized form of the Karplus-like equation that was used to parameterize the dependence of J-couplings on a specific torsion angle was first described by Pachler (K. G. R. Pachler, Extended Huckel Theory MO Calculations of Proton-Proton Coupling Constants-II: The Effect of Substituents on Vicinal Couplings in Monosubstituted Ethanes, Tetrahedron 1971, 27, 187-199). He proposed the use of this trigonometric function to account for asymmetry in the Karplus curve caused by substitution of a hydrogen atom in the coupling pathway. We adopted this trigonometric polynomial form because it provides the best parameterization to the DFT data with the smallest number of terms. This form of the equation is also amenable to simple integration which allowed us to develop the MA'AT equation for modeling torsional populations.