  We present results from simulations of regular pentagons arranged in a
rectangular die. The particles are subjected to vertical tapping. We study the
behavior of the packing fraction, number of contacts and arch distributions as
a function of the tapping amplitude. Pentagons show peculiar features as
compared with disks. As a general rule, pentagons tend to form less arches than
disks. Nevertheless, as the tapping amplitude is decreased, the typical size of
the pentagon arches grows significantly. As a consequence, a pentagon packing
reduces its packing fraction when tapped gently in contrast with the behavior
found in rounded particle deposits.
