Are any of you here comfortable with thermodynamic calculations for heterophase fluctuations? Then please help me understand an important bit in my book (attached) I am doing a project on nucleation, i.e. the study of building of clusters of different atoms. In my book (attached part) it seems important to consider what is called the equilibrium distribution of clusters, though in a system with an effective supersaturation this is apparantly just a theoretical distribution not a physical one. I would like some understanding on what the idea of considering this distribution is: When does it describe the physical distribution of clusters? And more importantly it relates the chemical potentials as per equation 7.3. Can anyone tell me how to arrive at this kind of dependence? I tried to check the reference but couldn't find the specific calculation.