Critical anomaly and finite size scaling of the self-diffusion coefficient for Lennard—Jones fluids by non-equilibrium molecular dynamic simulation

Abstract

We use non-equilibrium molecular dynamics simulations to calculate the self-diffusion coefficient, D, of a Lennard-Jones fluid over a wide density and temperature range. The change in self-diffusion coefficient with temperature decreases by increasing density. For density ρ * = ρσ 3 = 0.84 we observe a peak at the value of the self-diffusion coefficient and the critical temperature T * = kT /ε = 1.25. The value of the self-diffusion coefficient strongly depends on system size. The data of the self-diffusion coefficient are fitted to a simple analytic relation based on hydrodynamic arguments. This correction scales as N −α , where α is an adjustable parameter and N is the number of particles. It is observed that the values of α < 1 provide quite a good correction to the simulation data. The system size dependence is very strong for lower densities, but it is not as strong for higher densities. The self-diffusion coefficient calculated with non-equilibrium molecular dynamic simulations at different temperatures and densities is in good agreement with other calculations from the literature.

Enhancement of water self-diffusion at super-hydrophilic surface with ordered water

“…[39,40] Thus, it is generally accepted that there is a faster diffusion constant near the hydrophobic surfaces than near the hydrophilic surfaces. [39,[41][42][43][44][45][46][47][48] Till now, considering the unexpected hydrophobicity-like behaviour of the ordered water, whether the ordered water structures can enhance the novel diffusion behavior near a super-hydrophilic surface is still unknown.…”

Molecular dynamics simulation of self-diffusion coefficients for liquid metals

“…Molecular dynamics simulation is a powerful tool to predict structural thermodynamic and transport properties for various liquids. [13][14][15][16][17] In this work, the coefficients of self-diffusion for liquid metals are obtained by using the molecular dynamics (MD) method based on the embedded-atommethod (EAM) potential function. The simulated results show that self-diffusion increases with temperature and a good inverse linear relation exists between the natural logarithm of self-diffusion coefficients and temperature.…”

Anisotropic self-diffusion of fluorinated poly(methacrylate) in metal–organic frameworks assessed with molecular dynamics simulation

“…The entire MD simulation was composed of three phases in the following order: a high-temperature relaxation, an annealing, and a data acquisition. [18,19] Taking into consideration the material properties of the MOF itself, the parameters for the high-temperature relaxation were as follows: NVT was selected as the ensemble; the temperature was set to be 1000 K; atom-based computation was used for intermolecular interaction potentials for both electrostatic force and van der Waals force. Other parameters remained unchanged.…”