When the radially integrated charge is decomposed into
different components due to the AuNP, water, and ions, one
finds (see Figure 5) the contribution due to the nanoparticle to
compete against the other two factors. The contribution of ions
decays slowly as expected on the basis of the above RDF data.
More interesting is the behavior of water, since it shows a peak
with a width of about 2 nm, the peak position being close to the
maximum of ion distribution (see Figure 3). As further results
below for the distribution of water orientation will show, the
water behavior in Figure 5 largely arises from the complexity of
the ordering of water. Similar features over similar scales have
been observed for water close to its interface with charged lipid
membranes.65