  The effect of oscillatory shear strain on nonaffine rearrangements of
individual particles in a three-dimensional binary glass is investigated using
molecular dynamics simulations. The amorphous material is represented by the
Kob-Andersen mixture at the temperature well below the glass transition. We
find that during periodic shear deformation of the material, some particles
undergo reversible nonaffine displacements with amplitudes that are
approximately power-law distributed. Our simulations show that particles with
large amplitudes of nonaffine displacement exhibit a collective behavior;
namely, they tend to aggregate into relatively compact clusters that become
comparable with the system size near the yield strain. Along with reversible
displacements there exist a number of irreversible ones. With increasing strain
amplitude, the probability of irreversible displacements during one cycle
increases, which leads to permanent structural relaxation of the material.
