  Using molecular dynamics simulations, we have studied the atomic correlations
characterizing the second peak in the radial distribution function (RDF) of
metallic glasses and liquids. The analysis was conducted from the perspective
of different connection schemes of atomic packing motifs, based on the number
of shared atoms between two linked coordination polyhedra. The results
demonstrate that the cluster connections by face-sharing, specifically with
three common atoms, are most favored when transitioning from the liquid to
glassy state, and exhibit the stiffest elastic response during shear
deformation. These properties of the connections and the resultant atomic
correlations are generally the same for different types of packing motifs in
different alloys. Splitting of the second RDF peak was observed for the
inherent structure of the equilibrium liquid, originating solely from cluster
connections; this trait can then be inherited in the metallic glass formed via
subsequent quenching of the parent liquid through the glass transition, in the
absence of any additional type of local structural order. Increasing ordering
and cluster connection during cooling, however, may tune the position and
intensity of the split peaks.
