  We report a molecular dynamics simulation demonstrating that a columnar
liquid crystal, commonly formed by disc-shaped molecules, can be formed by
identical particles interacting via a spherically symmetric potential. Upon
isochoric cooling from a low-density isotropic liquid state the simulated
system performed a weak first order phase transition which produced a liquid
crystal phase composed of parallel particle columns arranged in a hexagonal
pattern in the plane perpendicular to the column axis. The particles within
columns formed a liquid structure and demonstrated a significant intracolumn
diffusion. Further cooling resulted in another first-order transition whereby
the column structure became periodically ordered in three dimensions
transforming the liquid-crystal phase into a crystal. This result is the first
observation of a liquid crystal formation in a simple one-component system of
particles. Its conceptual significance is in that it demonstrated that liquid
crystals that have so far only been produced in systems of anisometric
molecules, can also be formed by mesoscopic soft-matter and colloidal systems
of spherical particles with appropriately tuned interatomic potential.
