  We study crystallization in a model system for eicosane (C20) by means of
molecular dynamics simulation and we identify the microscopic mechanisms of
homogeneous crystal nucleation and growth. For the nucleation process, we
observe that chains first align and then straighten. Then the local density
increases and finally the monomer units become ordered positionally. The
subsequent crystal growth process is characterized by a sliding-in motion of
the chains. Chains preferably attach to the crystalline cluster with one end
and then move along the stems of already crystallized chains towards their
final position. This process is cooperative, i.e. neighboring chains tend to
get attached in clusters rather than independently
