  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.
