This approach was previously used to analyze the kinetics of hydrogen uptake by ball-milled lithium nitride. Hancock and Sharp state that linear plots result if a is limited to the range 0.15 to 0.50, which for the bulk material corresponds to ln(t) values between 6.78 and 7.46 and between 5.72 and 6.35 for the nanoscale material. However, as is evident in Figures S-2 and S-3, the linear regions of these plots are much broader than this. Region 0 contains only two data points for both bulk and nanoscale Li3N. Nevertheless, the fit yields a slope of 1.23 (Table -1), which corresponds almost exactly to the value expected for a zeroth-order process as found by Li et al.