Abstract
The mean-square displacement, r2(t), of a labeled particle hopping on a linear chain through a multicomponent dynamic background with vacancy concentration v is evaluated in the limit of extremely long times. We find r2(t)=[2va2(1v)12](J̃tπ)12, where J̃ is a collective hopping rate given by (ΣλxλJλ)1. Here Jλ is the hopping rate and xλ the concentration of the λth atomic species in the background.