  Event-driven molecular dynamics is a valuable tool in condensed and soft
matter physics when particles can be modeled as hard objects or more generally
if their interaction potential can be modeled in a stepwise fashion. Hard
spheres model has been indeed widely used both for computational and
theoretical description of physical systems. Recently further developments of
computational techniques allow simulations of hard rigid objects of generic
shape. In present paper we will present some optimizations for event-driven
simulations that offered significant speedup over previous methods. In
particular we will describe a generalization of well known linked list method
and an improvement on nearest neighbor lists method recently proposed by us.
