Practical Applications of Grand-canonical Electronic Structure Calculations in Electrochemical Simulation

Modeling electrified interfaces has long been a great challenge in electrochemistry. In recent years, the grand-canonical treatment for electrons has gradually been developed, and its combination with density functional theory has been widely used to simulate electrochemical processes on an atomistic scale. In this Perspective, we aim to discuss several practical applications of this powerful technique after a short review of necessary fundamentals. We will begin with capacitor-based parametrization method of grand-canonical calculated results. If considering the electrodes under different applied potentials as different materials, the parametrization can be viewed as a kind of "quadratic scaling relation", which might reduce the overall computational costs by data postanalysis rather than algorithm development. Following an example of the abnormal potential-independent energetic curve within the bandgap area, we turn the topic to the semiconducting electrodes. Meanwhile, the specific behaviors of the bandgap also indicate that besides the reaction thermodynamics and kinetics, the detailed electronic structure of the system can also be well described by the grand-canonical treatment on electrons. Several possibilities for further applications are proposed correspondingly and summarized at the end of paper. We believe that the grand-canonical treatment for electronic structure calculations can greatly enrich our understanding of the fundamental mechanisms under electrochemical environments.