Using the Gibbs free energies calculated above, it is possible to calculate the binding free energies under specific conditions of monomer concentrations and temperature. The selfconsistent distribution function proposed by Wilemski and Wyslouzil 44 was employed to establish the monomer free energies as zero. Figure shows the binding free energies of the clusters at 278.15 K. This temperature was selected as it corresponds to typical CLOUD chamber measurements and observations of nucleation in the field. We studied a low In all cases, the cluster growth becomes favorable for larger clusters. For AM at 10 ppt, we see a slight free energy barrier. This barrier is suppressed at 10 ppb of AM and the clusters form spontaneously. In both DMA cases ([DMA] = 1 or 10 ppt), we observe a barrier-free cluster formation process for the SA-DMA system. This is consistent with the CLOUD measurements, where SA-DMA nucleation is observed to occur at the collision limit. Overall, this illustrates that the usual assumption in cluster dynamics studies that the clusters are stable outside the eight-molecule area appears to hold for our current results.