Dynamics study on the non-adiabatic Na(3p) + HD → NaH/NaD + D/H reaction: insert-abstraction mechanism
Time-dependent wave packet calculations are carried out for two reaction channels of the non-adiabatic Na(3p) + HD → NaH/NaD + D/H reaction. The potential well on the excited state potential energy surface makes the reaction prefer to proceed through the insertion reaction path. The dominance of NaD + H reaction channel and product rotational state distributions are found to be in agreement with the characteristic of typical adiabatic insertion reactions. However, significant forward scattering peaks in the differential cross sections (DCS) are found to be inconsistent with the forward-backward symmetric scattering characteristic of typical adiabatic insertion reactions, which indicate that the Na(3p) + HD reaction is dominated by a direct reaction mechanism. The comparison between adiabatic and non-adiabatic calculated DCSs reveals that the non-adiabatic couplings in the reaction could reduce the lifetime of the intermediate complex. Finally, the insert-abstraction mechanism is put forward for the non-adiabatic Na(3p) + HD reaction.