Efficiently accounting for ion correlations in electrokinetic nanofluidic devices using density functional theory

► In this study, we examine the effect of finite ion size in nanofluidic devices. ► Counterintuitive phenomena occur with highly charged surfaces and multivalent ions. ► We model ions as charged, hard spheres using density functional theory (DFT). ► We conclude DFT may be a valuable design tool for multivalent nanofluidic devices.