As the size of the nanocrystal increases, the inter-ligand interactions increase, such that the van der Waals interactions are stronger, and the rotational restriction is greater. To illustrate this, the Ising model parameters are plotted against the calculated spherical curvatures of the indium phosphide quantum dots (Figure and). The curvature of a spherical particle can be represented as the inverse of its radius, such that a flat surface would have a curvature of zero, and a point would have an infinite curvature. While assuming that the particles are spherical is certainly an approximation, transmission electron microscope imaging of these samples indicates this is a reasonable approximation (Figure ). Assuming that surface ligands are isotropically distributed on the nanocrystal surfaces and that surface ligand densities are similar across samples, curvature should correlate with surface ligand interactions. As nanocrystal surface curvature decreases, the angle between the coordinated ligand tails should also decrease (Figure ), resulting in an increase of surface inter-ligand interactions. This increased ordering of ligands on low curvature nanocrystal surfaces has also been reported previously, most notably through careful NMR measurements on gold nanoparticles. For context, interaction terms for the previous study are included in the plots as well, although slight adjustments have been made to ensure uniformity in sizing and concentration calculations (see Supporting Information).