Once the singly occupied molecular orbital (SOMO) after one electron has been ionised from isolated Fc, the impact is on the centre Fe atom (a d-orbital) while Fc + keeps the same symmetry. As shown in Figure , the centre part of E-Fc at adsorption exhibits a net electron loss. The cross-sectional VCDD map at the position of Fe in Figure The bottom Cp of E-Fc in Figure (c) at adsorption attracts a greater degree of electron depletion and concentration. Interestingly, unlike the parallel adsorption configuration, the vertical adsorption configuration does not exhibit uniform charge accumulation on the surface Au atoms.