Abstract
The authors explore the coupling between rotations and translations through electrostatic interactions with the medium and show that it leads to non-Gaussian translational dynamics and violation of Stokes-Einstein-Debye relation.
Highlights
Following the classical work by Einstein [1], mobility of a colloidal particle in a liquid has been viewed as a result of random collisions of liquid’s molecules with the tagged particle [2,3,4]
The simulations done in roomtemperature simple point charge (SPC/E) force-field water aim at producing the dependence of rotational and translational dynamics of the solute on its dipole moment, which is altered by maintaining the distance between the charges while changing the partial charge q in small steps
We find that the continuum estimate τE = τEc for the electric field relaxation [Eq (12)] is much below τE reported by molecular dynamics (MD) (Fig. 16)
Summary
Following the classical work by Einstein [1], mobility of a colloidal particle in a liquid has been viewed as a result of random collisions of liquid’s molecules with the tagged particle [2,3,4]. How these general arguments will translate to changes of transport coefficients of a probe molecule placed in a polar liquid is not easy to predict This is because different interactions, mostly vdW and electrostatic interactions, compete in the overall time correlation functions constructed with forces and torques. The simulations done in roomtemperature simple point charge (SPC/E) force-field water aim at producing the dependence of rotational and translational dynamics of the solute on its dipole moment, which is altered by maintaining the distance between the charges while changing the partial charge q in small steps This setup has allowed us to test the basic predictions of classical theories of dielectric friction and contrast them with perturbation theories for the statistics of the electric field produced by the solvent inside the solute. By extending these results to low temperatures, we suggest that explaining SED violation in supercooled water [31,32] requires development of physical models including electrostatics in terms of dielectric friction
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
