From the GISAXS measurements, we obtained an interparticle distance of 12.2 ± 0.8 Å, which is somewhat larger than than the interparticle distance of the ∼ 3.2 nm large particles of 10.6 Å from the literature. Our simulated distance agrees very well with the interparticle distance of the larger particles, which is in agreement with theoretical predictions that the ligand structure of GNPs approaches that of flat, bulk surfaces with increasing particle size. It should, however, be kept in mind that both experiment and theory have error bars on the interparticle distances, which may affect the good agreement between theory and experiment, and the different between the GNPs.