Hard Spheres, Soft Spheres, and Experiment

Experimental Data

Matching \(\alpha_2\) Timescale

Simulation data is from hard spheres, with packing fraction (\(\phi\)) denoted in the legend.

Matching \(\alpha_2\) Timescale: MSD

Simulation data is for hard spheres at \(\phi=0.58\), for a simulation run as long as the experimental data in scaled time.

Crowding can yield similar \(\alpha_2\) values and MSDs as our experiments, but cannot match the width of the \(\alpha_2\) peak or the variability of the MSD.

\(\alpha_2\) Variability

There is high variability between trajectories, and less in each trajectory.

Characterizing Hard Spheres

Tuning "Soft" Interactions

WCA Potential

"Soft" spheres with an increasingly "sharp" potential become increasingly like hard spheres

Tuning "Soft" Interactions

Simulation data is for hard spheres (black), and a WCA for a simulation run as long as the experimental data in scaled time.

Tuning "Soft" Interactions

"Soft" spheres can also be steadily tuned to be more attractive.

Step Size Distributions

Step Size Distributions