The τ parameter was further optimized using results obtained with τ =20, 50, 100, and 200 ps. Fig. shows the q 3 distributions for different τ values. The threshold for identifying crystalline and glassy PS 4 3units was set at the midpoint between the maximum and minimum q 3 values for bulk 75Li Table summarizes the percentages of correctly identified units for bulk 75Li 2 S-25P 2 S 5 glass and β-Li 3 PS 4 with different τ values. The classification accuracies for τ =100 ps and 200 ps were sufficient for subsequent crystal growth analyses. Since higher time resolution is desirable for crystal growth studies, we adopted τ = 100 ps for all analyses in this study.