Pore-size dependence of quasi-one-dimensional single-file diffusion mobility

We use kinetic Monte Carlo simulation to study the pore-size dependence of the anomalous single-file diffusion mobility of a hard disc fluid confined within a narrow channel. The channel has a half-width of R _p in units of the hard disk diameter. We present numerical data on the crossover from the exact ID result with R _p = (1/2) to the quasi-ID regime for (1/2) < R _p < 1. Our data are significant because exact results in the quasi-ID regime are very limited. A scaling dependence of (R _p -(1/2)) ^4.65 is consistent with the measured increase in the mobility for almost seven decades.