Let us consider the usual expression for Diffusion processes and diffusion coefficients in the Eyring's theory:

$$D=\lambda^2k = \lambda^2 \frac{k_BT}{h}\frac{\Omega_\ddagger}{\Omega}e^{-\frac{\epsilon_0}{k_BT}}$$

I would like to use this formulation to relate molecular partition functions, molecular structure, and $D$. To do so for aqueous solutions, I need to take in account, while evaluating rotational and vibrational partition functions, that internal motion is closely related to hydrogen bonding.

I think that the main contribution to the alteration of degrees of freedom for a molecule in diffusion processes is the translational one, but taking in account that, it is likely that the movement of a molecule determines an alteration in the intermolecular interactions (which in water are not negligible). For that reason, I would like to know if there is a way to take that into account while evaluating the partition functions.

  • $\begingroup$ I gave my +1 long ago, but now that it has been almost 1 year, can you update us please? Are you still urgently or actively in need of an answer to this question? $\endgroup$ Dec 9, 2023 at 16:46
  • $\begingroup$ Sorry, I've been pretty involved in some other academic projects. I am actually still in search of an answer. I managed to find some useful papers on solvation entropy and configurational entropy scalings for D, but that isn't the same as what I asked here. $\endgroup$ Jan 15 at 14:11