Two factors were identified to highly affect the Soret coefficient value when predicted from EMD simulations: the mass-mass phenomenological coefficient and the difference between the partial molar enthalpies of both components (h 1 /M 1 -h 2 /M 2 ). For the majority of considered mixtures, a change of a few percent of either of these quantities leads to a large change of the Soret coefficient. For example, Figure shows the resulting changes of the Soret coefficient when the mass-mass phenomenological coefficient L 11 and the enthalpy difference (h 1 /M 1 -h 2 /M 2 ) are varied by ±10%. The strong variation of the Soret coefficient is related to L Q1 . As can be seen in Figure , the contribution of the enthalpy on the heat-mass phenomenological coefficient is large for most of the studied mixtures. Furthermore, in cases where terms of Equation 20 have a very similar magnitude a small change of the second term may even lead to a change of sign of the Soret coefficient. Because of the strong sensitivity of the EMD simulations for the studied mixtures, the results obtained from the larger systems featuring 8000 molecules are regarded as the more adequate values for comparison with NEMD results. The numerical results are listed in Table of the Supporting Information.