First-Principles Calculations of Electrochemical Capacitances of Nanometer-Scale Structures

Abstract

Quantum effects in electrochemical capacitances observed in the scanning tunneling microscopy study stimulate the theoretical work. We have applied new methods based on the density functional theory, which have been developed in our group, to the calculation of capacitances of jellium electrode with a nanometer-scale gap, an organic molecule, fullerenes and carbon nanotubes. Quantum effects and the electronic states origin in the capacitances have been elucidated through the first-principles calculations. We emphasize that the capacitance is not just a parameter but a key physical quantity manifesting the electronic states of nanostructures.