Figure 7.

Evidence for multicharge steps at low intercharge distance. (A and E) Chemical energy profiles for the multicharge models with an intercharge distance of either 8 or 4.5 Å. (B and F) Filtered current responses for the two models, showing that although at a relatively high intercharge distance, multiple peaks are clearly visible in the response, at lower intercharge distance often the passage of the four gating charges occurs in only one step. (C and G) Running integrals for the responses shown in (B) and (F). (D and H) Histograms of the charge carried by the current peaks, accumulated from 20 (D) or 60 (H) responses as those shown in (B) and (F). It is evident that for large intercharge distances, most of the current peaks carry a single gating charge, whereas for lower intercharge distance, peaks carrying multiple gating charges are significantly represented. To see this figure in color, go online.