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.
