and the anodic polarized Au(100) with Cl adsorption look almost the same. Given the size of cross-section of our simulation cell, an integer charge of -1e will lead to a surface charge density of about -20 µC/cm 2 . This means when one Cl ion adsorbed on an anodic polarized Au(100) with free charge of +8.2 µC/cm 2 (D = 0.018 au), one would expect to see a charge inversion with almost the same amount but an opposite type of charge. This