To test the accuracy of the mPB equation for suspensions with multivalent coions, we calculate the ionic density profiles for nanoparticles of fixed charge -Zq. Fig. shows ionic profiles around a nanoparticle of charge Z = 200, in a suspensions containing 1:3 electrolyte of various concentrations: c s = 20 mM (a), c s = 100 mM (b) and c s = 150 mM (c). A very good agreement is observed in all cases. The reason for such good agreement is due to the absence of strong electrostatic correlations between ions in the vicinity of the charged surface -because of their strong repulsion from the charged surface the concentration of multivalent coion remains low everywhere. We also note that, since ionic radius is small and the concentrations are not too large, the packing effects close to the surface are insignificant. As the result, steric interactions among the condensed counterions -which are completely neglected at the mean-field level -are negligible. Furthermore, since the counterions are monovalent, electrostatic correlations between them remain weak near the charged surface. The trivalent coions, on the other hand, are strongly repelled from the surface. Since the surface charge is not very large, the counterion concentration close to the surface is not sufficient to produce a neighboring layer of trivalent coions (the so-called layering effect), again signifying that ionic correlations are small in this range of ionic concentration and surface charge, and are well described by Eq. ( ). Similar trends can be observed in Fig. , which shows the density profiles for the same set of salt concentrations, but in a regime of much higher surface charge, Z = 1200. Despite the buildup of a much larger and thinner layer of counterions at the surface, the ionic correlations are not large enough to result in any significant deviation from the mean-field predictions. This again is a consequence of weak electrostatic correlations among monovalent counterions at the surface 1 . If counterions were trivalent and coions monovalent, the repulsion between neighboring counterions close to the surface would result in strong deviations from the mean-field predictions . It is thus important to emphasize that the validity of the mPB equation is restricted to the case of monovalent counterions and the surface charge and salt concentrations that are not too large. In the case of trivalent counterions, strong electrostatic correlations will restrict considerably the range of validity of the mean-field approach 1 . Perhaps the most interesting feature of the comparisons presented in Figs. and is the ability of the mPB equation to accurately describe the ionic depletion close to the cell boundary. This depletion is clearly more pronounced for multivalent coions and is a consequence of electrostatic correlations. The correlations between ions result in counterion clouds that screen ionic electric field inside the electrolyte. The distortion of the polarization cloud produced by the wall prevents efficient screening, resulting in a repulsion from the wall. This effect is stronger for trivalent ions, which feel greater repulsion from a neutral hard wall. In order to emphasize this point, in Fig. a comparison is shown between the distributions of monovalent and trivalent anions around a nanoparticle of charge Z = 600. In the case of 1 : 3 electrolyte, a larger depletion zone is observed around the nanoparticle, which is mainly of electrostatic nature. At the same time, a strong repulsion of trivalent anions from the neutral cell boundary can be seen. The mPB equation, therefore, captures the most important electrostatic correlation effects present in 1:z electrolytes. This is not the case for the usual PB equation without the electrostatic solvation correction, in which case the profiles near a hard wall remain the same as in the bulk. We should stress that a proper description of such depletion effect is quite important, since the contact theorem 100-105 allows us to connect the ionic density at the hard wall with the osmotic pressure that exists inside the suspension.