  We use computer simulations to explore the manner in which the particle
displacements on intermediate time scales in supercooled fluids correlate to
their dynamic structural environment. The fluid we study, a binary mixture of
hard spheres, exhibits classic signatures of dynamic heterogeneity, including a
bifurcated single-particle displacement distribution (i.e., subpopulations of
immobile and mobile particles). We find that immobile particles, during the
course of their displacements, exhibit stronger average pair correlations to
their neighbors than mobile particles, but not necessarily higher average
coordination numbers. We discuss how the correlation between structure and
single-particle dynamics depends on observation time.
