“…͑7͒ to ͑9͒, the superscripts s, c, and e refer to the stochastic fluctuations due to the random migratory jumps, random cascade initiation, and random vacancy emission, respectively. Note also that D e is proportional to the void surface area, 17,18 instead of to the void radius, as usually assumed in most other studies. The dependence of D e on the void size was discussed in detail in Ref.…”