  We study the relationship between local structural ordering and dynamical
heterogeneities in a model glass-forming liquid, the Wahnstrom mixture. A novel
cluster-based approach is used to detect local energy minimum polyhedral
clusters and local crystalline environments. A structure-specific time
correlation function is then devised to determine their temporal stability. For
our system, the lifetime correlation function for icosahedral clusters decays
far slower than for those of similarly sized but topologically distinct
clusters. Upon cooling, the icosahedra form domains of increasing size and
their lifetime increases with the size of the domains. Furthermore, these
long-lived domains lower the mobility of neighboring particles. These
structured domains show correlations with the slow regions of the dynamical
heterogeneities that form on cooling towards the glass transition. Although
icosahedral clusters with a particular composition and arrangement of large and
small particles are structural elements of the crystal, we find that most
icosahedral clusters lack such order in composition and arrangement and thus
local crystalline ordering makes only a limited contribution to this process.
Finally, we characterize the spatial correlation of the domains of icosahedra
by two structural correlation lengths and compare them with the four-point
dynamic correlation length. All the length scales increase upon cooling, but in
different ways.
