Development of a dielectrically consistent reference interaction site model combined with the density functional theory for electrochemical interface simulations

Abstract

The dielectrically consistent reference interaction site model (DRISM) is one of the methods used to solve the well-known drawback of the reference interaction site model (RISM) theory: That it underestimates the dielectric constant of the solutions. Recently, Nishihara and Otani developed the first-principles effective screening medium (ESM) method combined with RISM theory, called ESM-RISM, to simulate physical properties at the electrode/electrolyte interface [Phys. Rev. B 96, 115429 (2017)]. In this study, we combined DRISM with the ESM-RISM framework to increase the accuracy of electrochemical interface simulations, which was applied to the Pt(111)/aqueous water interface as a benchmark calculation. The electrochemical properties at the interface, such as the potential of zero charge, standard hydrogen electrode potential, and double-layer capacitance, all reasonably agree with previous experiments. The thickness of the contact layer was found to correlate well with double-layer capacitance. We believe that the present method is a useful tool to better model the physical properties at electrochemical interfaces.