  Atomistic deformation simulations in the nominally elastic regime are
performed for a model binary glass with strain rates as low as $10^{4}$/sec
(corresponding to 0.01 shear strain per 1$\mu$sec). A robust elasticity is
revealed that exhibits only minor elastic softening, despite quite different
degrees of structural relaxation occurring over the four orders of magnitude
strain rates considered. A closer inspection of the atomic-scale structure
indicates the material response is distinctly different for two types of local
atomic environments. A system spanning iscosahedrally coordinated substructure
responds purely elastically, whereas the remaining substructure also admits
microplastic evolution. This leads to a heterogeneous internal stress
distribution which, upon unloading, results in negative creep and complete
residual-strain recovery. A detailed structural analysis in terms of local
stress, atomic displacement, and SU(2) local bonding topology shows such
microscopic processes can result in large changes in local stress and are more
likely to occur in geometrically frustrated regions characterized by higher
free volume and softer elastic stiffness. These insights shed atomistic light
onto the structural origins that may govern recent experimental observations of
significant structural evolution in response to elastic loading protocols.
