Quantum capacitances of molecules, fullerenes and carbon nanotubes by the partitioned real-space density functional method

Capacitances of molecules, fullerenes and carbon nanotubes under the condition of no electron-tunneling are calculated by the partitioned real-space density functional method that has been recently developed. We found that a quantum capacitance of a spherical jellium bielectrode decreases and approaches the classical value as the electron density increases. The capacitances of fullerenes and carbon nanotubes do not depend on the detailed atomic geometry but on the overall shapes. The values of the capacitances of these nanostructures are found to be a few 10-20 F and are compatible with the experimental ones determined by the scanning tunneling microscopy studies