Non-Equilibrium Molecular Dynamics simulation of diffusion in nonuniform nanochannels

Free energy landscape of complex system, when represented as a function of an order parameter or reaction coordinate, presents many local minima that separated with barriers. The nature of this barrier depends on which thermodynamic potential varies when passing from one potential well to other, and their presence plays an important role in dynamics of system. Energy barriers are more frequent, but also there is an entropy barrier that is not as familiar as energy barrier. We encounter this barrier in soft condense matter and biological systems [1]. Diffusion of fluid in varying cross section channels is a kind of these systems. In this work, we studied Non-Equilibrium Molecular Dynamics (NEMD) simulation of diffusion of a fluid in varying cross section nanochannel.