Molecular simulation of transport in nanopores: application of the transient-time correlation function formalism.

We report on nonequilibrium molecular dynamics (NEMD) simulation results on the color conductivity of fluids confined in cylindrical nanopores. Because conventional NEMD methods are restricted to fields several orders of magnitude stronger than those accessible by experiment, these methods have provided access so far only to the response of the fluid under far-from-equilibrium conditions. Using the transient-time correlation function formalism, we show how NEMD simulations can be extended to study the conductivity of a model liquid confined in a cylindrical nanopore and subjected to an arbitrarily low (and realistic) field. Our results provide a full picture of the dependence of conductivity on the applied field and on the effective diameter of the nanopore. They also demonstrate that the conductivity steadily increases-up to twice the value evaluated for the bulk-as the effective radius of the pore decreases.