were used to estimate the temperature jumps at the interface. Notably, differences in λ and G for the Chong and Wright citrate models and neat water are relatively small, indicating that the water is dominating the thermal transport in this system. In order to aid in interpreting differences in behavior between the planar and nanoparticle systems, the number densities, n(z) and n(r), for the various species are shown in Figure . We observe that water dominates the first solvation layer directly adjacent to the gold nanospheres, while the citrate and sodium ions have their highest concentrations in the second and third solvation layers. In the planar systems, the citrate (and sodium) have some presence immediately above the first solvation layer, and have appreciable concentrations extending up to 30 Å away from the surface. Top: Simulations using a non-polarizable model (EAM) for the metal. Bottom: Simulations using the DR-EAM polarizable model for the metal. Note, in all figures, the number densities of the citrate ions and sodium counter-ions have been multiplied by a factor of 100 to aid visibility. Notably, the water and ions surrounding the nanospheres are significantly less structured in the interfacial layers compared with the planar interfaces. Surface polarizability appears to have only a minor influence on the density of any species as a function of distance from the surface. Each curve is an average of 10 statistically independent simulations. Fig. illustrates typical thermal profiles (T (r)) for both the non-polarizable and polarizable nanoparticle systems. Fits from Eq. ( ) are also shown, and we note that these provide a relatively poor representation of solvent layering effects.