Combinations of (A s,wat , A s,dod ) that produced contact angles under 30 • were challenging to simulate since the explicit droplets tend to spread out, in particular, for the smaller system sizes. Other combinations generated detached droplets that we did not analyse. To understand these behaviours, we return to the de Gennes spreading parameter defined in Eq. ( ). Here, we use the smoothed versions of surface energies in Eqs. (9) to calculate S as a function of (A s,wat , A s,dod ), noting that for this purpose γ wat,dod = 27.3 ± 0.4 mN m -1 is a constant dictated by the coarse-grained water-plus-dodecane model. Fig. shows the behaviour of the droplet on the surface as predicted by S. Corresponding to the classification scheme in the introduction, three regimes are observed. In the lower right region, S > 0 and the droplet spreads out. In the upper left region, S < -2γ wat,dod corresponds to droplet detachment. In the middle region, where -2γ wat,dod < S < 0, partial wetting is observed, with the droplet sitting on the surface with a finite contact angle as indicated by the color scale. The boundary between the droplet spreading regime and finite contact angle regime corresponds to the boundary we have seen in the simulations.