Figure shows the charge redistribution caused by the excitation of O atoms, corresponding to the farthest and nearest position to Vo 2+ , respectively. The blue part represents the region with more charge after excitation, while the red part stands for less charge. After excitation, part of the electrons in sp 3 hybrid orbitals are pulled back to the nuclear region due to the increase of effective core charge. It is noted that the charge redistribution is local and very similar for the two O atoms with the highest and lowest CLS, respectively. This result indicates that the effect of Vo 2+ on its nearby O atoms is limited, which limits the possibility of significant Δ B.E. in XPS. This conclusion is quite important. Considering the crucial role played by Vo in metal oxides , the misinterpretation of XPS result may lead to wrong conclusions when trying to correlate Vo with certain materials properties, which can, in turn, further misguide research directions.