The contact peak happens at a distance slightly larger than the position of the pmf global minimum and, as noticed in the distribution of hydrophobic NPs in C4 and of hydrophilic NPs in C8, it is composed of two very close peaks which are almost superimposed. Those features results from contacts between different faces of the NPs as shown in Figure . The pmf calculations started from the dimer with the maximum number of contacts (left of Figure ), which renders the stronger interaction between the NPs and a distance between centers of mass of 4.46 nm, the position of the pmf global minimum. However, this structure was not formed spontaneously in the simulations of the NPs dispersions, instead, dimers with slightly larger distances between particles centers were formed (middle and right of Figure ), rendering g(r)