Dresden 2006 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 46: Poster
DY 46.74: Poster
Donnerstag, 30. März 2006, 16:00–18:00, P1
Computer Simulation of Stochastic Dynamics in Hard-Sphere Systems — •Thomas Voigtmann1, Cristiano De Michele2, and Antonio Scala2 — 1University of Edinburgh, U.K. — 2Universita di Roma "La Sapienza", Italy
The hard-sphere system, and derived systems like the square-well system (hard spheres with added square-well attraction) are useful models for understanding the dynamics of soft condensed matter. There, one is interested in their stochastic dynamics, i.e. the many-body Langevin equation with step-wise discontinuous pair potentials. Computer simulation (called Stochastic Dynamics, or Brownian Dynamics in the limit of vanishing inertial terms) is a helpful tool to gain insight here. But conventional algorithms are restricted to smooth potentials, where one can discretize the equations using some small time step. Hard spheres, on the other hand, need to be simulated with an event-driven algorithm; but this method does not work a priori for Brownian dynamics. Monte-Carlo-inspired schemes exist, but they have potential problems arising from the occurence of overlapping particles. We discuss a method to implement Brownian Dynamics and Stochastic Dynamics in hard spheres based on an event-driven algorithm. The accuracy of this method is assessed, and we discuss extensions to square-well systems and external forces, that are not easily achieved with previous methods.