Fig. 4

Molecular dynamics for H⁺ + H₂O⁺ + C₂H₃⁺. a–l Newton and m–x Dalitz plots for the triple coincidence channel H⁺ + H₂O⁺ + C₂H₃⁺. Panels a–d and m–p are for 0–5 eV KER and e–l and q–x are for 5 to 13 eV KER. The high KER region is split into e–h and q–t which shows the dynamics for the events with p < 20 a.u. and i–l and u–x for the events with p > 20 a.u. The time bins are the same for each column and are from left to right 0–150, 260–410, 460–610, and 660–810 fs (with the center of the time bin denoted). Note that the ellipses are only drawn to help guide the eye, and the color scale, given on the left of the plots range from less counts (bluer) to higher concentration of counts (redder). The blue, green and red shaded boxes show snapshots of the final states reached after the pump step in typical trajectory calculations for the three channels leading to H⁺ + H₂O⁺ + C₂H₃⁺ after the probe step: low KER, high KER inner arch, and high KER outer arch, respectively. Movie frames for the earlier stages of the corresponding fragmentation processes are given in the SI. Panel y shows Dalitz plot simulations considering different breakup mechanisms. Features labeled i (blue), ii (green), and iii (red) are for sequential bond breaking with C₂H₃⁺, H₂O⁺, and H⁺ being the first fragment ejected, respectively, and can be related via color to the first step of the breakup processes shown in the shaded boxes of (b)