Sliding diffusivity with per-step dissociation (${\tau }_b\simeq a^2/(2DP),{\ell }_{rms}\simeq a/\sqrt{P}$)

For an unbiased one-dimensional walk with step size $a$, diffusion coefficient $D$ fixes step interval $a^2/(2D)$. A small dissociation probability $P$ per step gives about $1/P$ steps before release. Thus lifetime depends on $D$, while the root-mean-square net displacement before release is $a/\sqrt{P}$. Net displacement is not the cumulative distance along all backtracking steps. Dimensional consistency of the measured or assumed diffusivity is necessary before applying the estimate.