Brownian dynamics simulations with hard-body interactions: Spherical particles

TL;DR

This paper introduces a new method for simulating hard-body interactions in overdamped Brownian dynamics, using transition probabilities on a half-line, applicable to systems with fixed obstacles or spherical particles, validated through numerical experiments.

Contribution

The paper presents a novel algorithm that accurately incorporates hard-body interactions in Brownian dynamics simulations, extending existing methods to systems with non-zero force fields.

Findings

Algorithm effectively models colloids in flow fields.

Method accurately captures protein interaction dynamics.

Numerical validation confirms algorithm's reliability.

Abstract

A novel approach to account for hard-body interactions in (overdamped) Brownian dynamics simulations is proposed for systems with non-vanishing force fields. The scheme exploits the analytically known transition probability for a Brownian particle on a one-dimensional half-line. The motion of a Brownian particle is decomposed into a component that is affected by hard-body interactions and into components that are unaffected. The hard-body interactions are incorporated by replacing the affected component of motion by the evolution on a half-line. It is discussed under which circumstances this approach is justified. In particular, the algorithm is developed and formulated for systems with space-fixed obstacles and for systems comprising spherical particles. The validity and justification of the algorithm is investigated numerically by looking at exemplary model systems of soft matter, namely at colloids in flow fields and at protein interactions. Furthermore, a thorough discussion of properties of other heuristic algorithms is carried out.