where ρ bulk i are the bulk values for the densities of the ions and water molecules (e.g., ρ bulk Na + = 0.1 mM, ρ bulk Cl -= 0.1 mM, and ρ bulk H 2 O = 55.5 M). Poisson's equation is solved to calculate the electrostatic potential (ϕ(r)). The resulting system of equations is solved iteratively to self-consistency using the relaxed Gummel iterative procedure. Chemical potential calculations utilize the notion that although the total chemical potential for each of the species is constant, individual components of chemical potential are position dependent, vary with local concentration and reflect the nature of the driving forces for nucleation and growth: