Fragmentation of Na3+ clusters by He impact: effect of initial cluster temperature on non-adiabatic phenomena

A theoretical study has been carried out of the fragmentation of Na3+ ions following a collision with He. The collision leaves Na3+ in any of three electronic states, and each of these can fragment into three product channels (Na2++Na, Na2+Na+ and Na+Na+Na+). The Na3+ system has a conical intersection and an avoided crossing; these permit transitions between the different states. Cross-sections for each of the nine fragmentation pathways are presented for three different values of the initial vibrational excitation of Na3+. The cross-sections are very sensitive to this vibrational energy.