Resonance dynamics of DCO ($\widetilde{X}\,{}^2A'$) simulated with the dynamically pruned discrete variable representation (DP-DVR)

TL;DR

This paper uses the newly developed DP-DVR method to compute and analyze resonance states of the deuterated formyl radical, comparing theoretical decay and energy distributions with experimental data, and examining vibrational energy redistribution.

Contribution

The paper applies the recently introduced DP-DVR method to study resonance states of DCO, providing detailed analysis of decay, distributions, and vibrational energy redistribution, with validation against experimental results.

Findings

Good agreement between theoretical and experimental energy distributions.

C=O stretch quantum number is conserved during decay.

Strong anharmonic coupling affects zero-order state contributions.

Abstract

Selected resonance states of the deuterated formyl radical in the electronic ground state ($\widetilde{X}\,{}^2A'$) are computed using our recently introduced dynamically pruned discrete variable representation (DP-DVR) [H. R. Larsson, B. Hartke and D. J. Tannor, J. Chem. Phys., 145, 204108 (2016)]. Their decay and asymptotic distributions are analyzed and, for selected resonances, compared to experimental results obtained by a combination of stimulated emission pumping (SEP) and velocity-map imaging of the product D atoms. The theoretical results show good agreement with the experimental kinetic energy distributions. The intramolecular vibrational energy redistribution (IVR) is analyzed and compared with previous results from an effective polyad Hamiltonian. Specifically, we analyzed the part of the wavefunction that remains in the interaction region during the decay. The results from the polyad Hamiltonian could mainly be confirmed. The C=O stretch quantum number is typically conserved, while the D-C=O bend quantum number decreases. Differences are due to strong anharmonic coupling such that all resonances have major contributions from several zero-order states. For some of the resonances, the coupling is so strong that no further zero-order states appear during the dynamics in the interaction region, even after propagating for 300 ps.