Three-body predissociation of D₃and H₃3²A′(2sa′₁): wave packet dynamics and momentum correlation

Abstract

Predissociation of the short-lived 3 2A′(2sa′1) state of D3 and H3 is studied by three-dimensional wave packet dynamics on the pair of coupled ground state potential energy surfaces. Momentum correlation diagrams for the three-body fragmentation via non-adiabatic transition to the unstable electronic ground state are calculated for the lowest eight vibrational levels (and J = 0). Compared to previous semiclassical methods, the agreement with experimental results is improved.

Imaging of spatial many-body wave functions via linear momentum measurements

“…A more conclusive answer can only come from studies which include this wave packet propagation. Recent attempts 13,15 to include this propagation provide no closer agreement with the experimental data but rather predict additional nodal features not observed in the current experiments. A possible reason is the lack of experimental resolution, a problem which may be overcome in current experiments which aim at extending the statistics from 10 4 to 10 5 events per Dalitz map.…”

Lanczos wave packet propagation on coupled potential energy surfaces: the three body predissociation of rotating D3and H3${{3}^{2}}{{A}^{\prime }}$($2sa_{1}^{\prime }$)

“…Better results can be obtained with wave packet dynamics. However due to the simple but inefficient technique of complete Hamiltonian matrix diagonalization our previous calculations [14] were confined to small basis sets and the rotational quantum number J = 0.…”

“…A concluding discussion of our computational approach is to be found in section 5. All dynamical calculations were performed in hyperspherical coordinates, which are explained in the appendix of [14].…”

“…show potential minima at D h 3 geometry. Hyperspherical coordinates ρ, ϑ and φ, which are used to characterize the nuclear triangle configuration of our triatomic molecule, are defined in the appendix of [14] and in [6]. The circumference of the nuclear triangle is proportional to the hyper-radius ρ, whereas its shape ist determined by the hypersperical angles ϑ and φ.…”

“…A nonadiabatic transition to the system of the ′ pe 2 ground state surfaces induces the predissociation process. The transition operators Λ l u of vibrational coupling [10,14], where l and u denote the lower and upper adiabatic sheet of the electronic ground state, act on the initial states Ψ ν ν l JK s ,2 1 2 2 . These operators with ϑ ϑ π = + ˜2 4 contain derivative matrix elements between the adiabatic electronic states ψ l u ad and ψ s 2 ad as well as differential operators in nuclear configuration space.…”