  We present a coarse-grained single-site potential for simulating chiral
interactions, with adjustable strength, handedness, and preferred twist angle.
As an application, we perform basin-hopping global optimisation to predict the
favoured geometries for clusters of chiral rods. The morphology phase diagram
based upon these predictions has four distinct families, including previously
reported structures for potentials that introduce chirality based on shape,
such as membranes and helices. The transition between these two configurations
reproduces some key features of experimental results for {\it{fd}}
bacteriophage. The potential is computationally inexpensive, intuitive, and
versatile; we expect it will be useful for large scale simulations of chiral
molecules. For chiral particles confined in a cylindrical container we
reproduce the behaviour observed for fusilli pasta in a jar. Hence this
chiropole potential has the capability to provide insight into structures on
both macroscopic and molecular length scales.
