  The methodology to simulate transport phenomena in bulk systems is
well-established. In contrast, there is no clear consensus about the choice of
techniques to model cross-transport phenomena and phoretic transport, mainly
because some of the hydrodynamic descriptions are incomplete from a
thermodynamic point of view. In the present paper, we use a unified framework
to describe diffusio-osmosis(phoresis), and we report non-equilibrium Molecular
Dynamics (NEMD) on such systems. We explore different simulation methods to
highlight some of the technical problems that arise in the calculations. For
diffusiophoresis, we use two NEMD methods: boundary-driven and field-driven.
Although the two methods should be equivalent in the limit of very weak
gradients, we find that finite Peclet-number effects are much stronger in
boundary-driven flows than in the case where we apply fictitious color forces.
