Stable excited dication: trapping on the S₁ state of formaldehyde dication after strong field ionization

Abstract

Combined theoretical and experimental work examines the dynamics of dication formaldehyde produced by strong field ionization. Trajectory surface hopping dynamics on the first several singlet electronic states of formaldehyde dication...

Strong Field Double Ionization of Formaldehyde Investigated Using Momentum Resolved Covariance Imaging and Trajectory Surface Hopping

“…However, we calculated the potential energy as a function of C–H bond length for the first several states of the dication, and the states that lead to H + /HCO + have a very low slope at the Franck Condon location, which suggests that the difference in wavefunction width does not lead to a substantial difference in final KER width. This is shown in Figure in our recent work . In fact, our calculations show that the dominant contributions to the width of the KER distributions do not come from the spatial width of the initial wave function but rather from the fact that there are broad vibrational distributions in the final dissociation products.…”

“…This is shown in Figure 4 in our recent work. 38 In fact, our calculations show that the dominant contributions to the width of the KER distributions do not come from the spatial width of the initial wave function but rather from the fact that there are broad vibrational distributions in the final dissociation products.…”

“…While this will not affect the central position of the KER distributions, in principle, this could lead to a difference in the width of the KER distributions, depending on how steep the PES of the dicationic state is at the Franck Condon point. We did perform measurements for H (which are reported in a separate manuscript 38 This comparison shows that the KER distributions for this channel are very similar for the deuterated and undeuterated molecules. Measurements for the other channel reported in the manuscript (D + /DCO + ) were not possible because it was difficult to isolate H + fragment ions in our time of flight mass spectrum.…”

“…While this will not affect the central position of the KER distributions, in principle, this could lead to a difference in the width of the KER distributions, depending on how steep the PES of the dicationic state is at the Franck Condon point. We did perform measurements for H (which are reported in a separate manuscript in more detail). A comparison of the results for the (O + /CH 2 + ) and (O + /CD 2 + ) dissociation channels is shown in Figure .

8 KER spectra for (O + /CH 2 + ) and (O + /CD 2 + ) dissociation channels.

This comparison shows that the KER distributions for this channel are very similar for the deuterated and undeuterated molecules.…”

Light-induced photodissociation in the lowest three electronic states of the NaH molecule

“…Although many of these works treat the dynamical problem of diatomics starting investigations from the simplest hydrogen-like ions or molecules to systems with large numbers of electrons, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] other relevant papers are tackling the problem of photodissociation and fragmentation of polyatomics, as well. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Molecular dissociation is usually treated within the Born-Oppenheimer (BO) framework, which relies on the separation of the motions of the electrons and nuclei due to different time scales of their motion. In most cases, this approach works well and provides an acceptable treatment of dynamical processes.…”