In this case, a very weak laser field with ω 0 = 3.07 eV and E 0 max = 0.65 V/Å is applied. As Figure shows, the duration of scattered field at the center of mass of Au 20 @H 2 O is much longer than the incident field, the scattered field's amplitude is magnified about three-fold so that the OH bond disassociates even with a weak laser field. Figure displays the evolution of OH bonds in Au 20 @H 2 O which is interacting with the two kinds of fields, respectively. In the laser activity window, in the case with a uniform field, the change of OH bond length shows an "upward arc", while in the real near field case, it shows as a "downward arc". The near field generated from LSPR is a very short-range electromagnetic field with a strong intensity gradient which may generate gradient force to affect the molecule. To explain why the field's spatial distribution can affect the evolution of OH bonds with the time, we compare the forces acting on H 2 O molecule in Figure and Figure .