Electronically Nonadiabatic Effects on the Quantum Dynamics of the Ha + BeHb+ ? Be+ + HaHb; Hb + BeHa+ Reactions

Nonadiabatic effects are ubiquitous and play an important role in many chemical processes. Here, the adiabatic and nonadiabatic quantum scattering calculations of the H + BeH+ reaction are performed using the time-dependent wave packet method based on an accurate diabatic potential energy matrix that includes the lowest two electronic states and their couplings. The resulting integral cross sections reveal that the nonadiabatic effect significantly inhibits the reactivity of the BeH+-depletion channel but enhances that of the H-exchange channel. The vibrational excitation is suppressed, but the translational excitation is promoted for the H2 product in the BeH+-depletion channel when the nonadiabatic coupling is included. However, the nonadiabatic coupling has a mild effect on the H-exchange product-state distribution. When the nonadiabatic effect is considered, the differential cross sections of the H-2 product become less polarized because of the formation of an excited-state complex, whereas the corresponding results of the H-exchange channel only present an increase in the magnitude at the backward region.

Automated summary

The study reveals that nonadiabatic effects have different impacts on the reaction channels of H + BeH+, inhibiting the reactivity of the BeH+-depletion channel while enhancing that of the H-exchange channel. When nonadiabatic coupling is considered, vibrational excitation for the H2 product is suppressed but translational excitation is promoted.