Nonadiabatic effects in the pseudorotational motion of triatomic molecules

Electron-nuclear-dynamics theory simulations have been performed with the aim to understand the dynamic aspects of triatomic molecules in pseudorotational motion. More specifically, the units H₃⁺ and Li₃⁺ are investigated close to the threshold of dissociation. For both species, the dynamic response of the electronic system to the nuclear motion is examined by the computation of electronic angular momentum expectation values. The respective results differ markedly for α- and β- spin orientations, reflecting the emergence of rapid spin oscillations. This phenomenon is investigated by a detailed analysis of the electronic excitation content in both molecules. This is achieved by projection of the dynamic wave function on adiabatic electronic states that are evaluated along the nuclear trajectories. From an examination of the phase relations between expansion coefficients for electronic excitations with α- and β-spin orientation, we conclude that the systems maximize the observed spin polarization effects.