Nonequilibrium molecular dynamics study of thermal diffusion behavior of the MMSV potential model for hydrogen

Thermal diffusion factor and thermal conductivity of a binary isotopic fluid composed of H-2 and D-2 with a realistic intermolecular potential, namely Morse-Spline-Van der Waals (MSV), are computed at different densities and temperatures performing a newly developed non-equilibrium molecular dynamics algorithm. To achieve a deeper understanding of the thermal diffusion process at the molecular level, we investigate the effect of the shape interaction parameter of our model system on the thermal diffusion factor. We show that the thermal diffusion factor slightly increases with increasing the steepness of repulsive portion of the potential at low density, but strongly increases at high density. We also observe that the thermal conductivity is a weak function of the repulsive part of the potential at low density, but it depends strongly on the steepness of repulsive part of the potential at high-density.