In assessing the contribution of ∆G self i,i and ∆G solv i,j terms, water was found to be a large source of deviation. The ∆G self i,i of water was predicted to be overly negative, suggesting we over-estimate the strength of the water-water interactions. We gained further insight into this contribution by breaking down the ∆G solv i,j analysis into cases where water was the solute (i =water), water was the solvent (j =water), and where water was neither the solute or solvent. We found that when water was the solute, ∆G solv i,j / (RT) is predicted to be overly negative on average by 3.4 (dimensionless units) in the SM12 model as compared to the self-solvation free energy term ∆G self i,i / (RT) which was overly negative by 3.8 (dimensionless units). This deviation ends up being advantageous in discerning how to calculate limiting activity coefficients, as there were two methods in which to do so: 1) prediction of ∆G self i,i and ∆G solv i,j and use of reference values for the molar volume, and 2) compute ∆G self i,i using pure component vapor pressure data, which is readily available. We evaluated these two methods using three reference data sets: the Minnesota Solvation Database, Parts 1 to 6 of DECHEMA's "Activity Coefficients at Infinite Dilution" volumes , and "Yaws' Handbook of Properties for Aqueous Systems" . All three methods told the same story, where at first glance there does not appear to be a significant difference in the predictions when ∆G self i,i is predicted or computed from reference data. However, upon isolating systems where water is the solute, we see a that ln γ ∞ i,j is under-predicted when ∆G self i,i is computed from reference vapor pressure data. Yet when both ∆G self i,i and ∆G solv i,j are predicted there is a convenient cancellation of errors in the ln γ ∞ i,j . Therefore this suggests that the best method to calculate limiting activity coefficients moving forward is to compute ∆G self i,i and ∆G solv i,j consistently; that is, to predict both terms.