(color online) (a) Effective Stokes–Einstein diameter d determined by the calculated D and η. The dashed line is the first nearest-neighbour distance derived from g(r), 2.8 Å, which is nearly independent of temperature. The dotted-dashed line is the fitting result for d. Correlation coefficient for , and 0.79 for . (b) Parameter versus temperature. The lines are the linear fittings with and 0.86 for the low and high temperature ranges separated by , respectively.