Extraction of self-diffusivity in systems with nondiffusive short-time behavior.
We consider a toy model that captures the short-time nondiffusive behavior seen in many physical systems, to study the extraction of self-diffusivity from particle trajectories. We propose and evaluate a simple method to automatically detect the transition to diffusive behavior. We simulate the toy model to generate data sets of varying quality and test different methods of extracting the self-diffusion coefficient and characterizing its uncertainty. We find that weighted least-squares with statistical bootstrap is the most accurate and efficient means for analyzing the trajectory data. The analysis suggests an iterative recipe for designing simulations to conform to a specified level of accuracy.
Department of Scientific Computing, Florida State University, Tallahassee, Florida 32306, USA.
Sachin
S
Shanbhag