  We study numerically the crystallization of a hard-sphere mixture with 8\%
polydispersity. Although often used as a model glass former, for small system
sizes we observe crystallization in molecular dynamics simulations. This opens
the possibility to study the competition between crystallization and structural
relaxation of the melt, which typically is out of reach due to the disparate
timescales. We quantify the dependence of relaxation and crystallization times
on density and system size. For one density and system size we perform a
detailed committor analysis to investigate the suitability of local structures
as order parameters to describe the crystallization process. We find that local
structures are strongly correlated with generic bond order and add little
information to the reaction coordinate.
