Size dependence of solute?s translational jump-diffusion in solvent: Relationship between trapping and jump-diffusion

Previous studies, explaining the breakdown of Stokes-Einstein relation using the translational jump-diffusion (TJD) approach, hinted an important relationship between the strength of solute trapping inside solvent cage and the contribution of jump-diffusion to the total diffusion. To generalize the above picture we simulate here a simple solute-solvent model system with different solute sizes. It has been observed that the jump-diffusion contribution is negligible when the solute particles are weakly trapped within the solvent cage and vice versa. This study, therefore, suggests that strong caging induces jump-diffusion of a particle, which is responsible for the breakdown of Stokes-Einstein relation.