Accession Number:

AD1088869

Title:

Ab initio Investigation of Br-3d Core-Excited States in HBr and HBr+ Toward XUV Probing of Photochemical Dynamics

Descriptive Note:

Journal Article - Open Access

Corporate Author:

University of California Berkeley Berkeley United States

Report Date:

2019-01-30

Pagination or Media Count:

10.0

Abstract:

Ultrafast X-rayXUV transient absorption spectroscopy is a powerful tool for real-time probing of chemical dynamics.Interpretation of the transient absorption spectra requires knowledge of core-excited potentials, which necessitates assistance from high-level electronic-structure computations. In this study, we investigate Br-3d core-excited electronic structures of hydrogen bromide HBr using spin-orbit general multiconfigurational quasidegenerate perturbation theory SO-GMC-QDPT.Potential energy curves and transition dipole moments are calculated from the Franck-Condon region to the asymptotic limit and used to construct core-to-valence absorption strengths for five electronic states of HBr and two electronic states of HBr. The results illustrate the capabilities of Br-3d edge probing to capture transitions of the electronic-state symmetry as well as nonadiabatic dissociation processes that evolve across avoided crossings. Furthermore, core-to-valence absorption spectra are simulated from the neutral state and the ionic states by numerically solving the time-dependent Schroedinger equation and exhibit excellent agreement with the experimental spectrum. The comprehensive and quantitative picture of the core-excited states obtained in this work allows for transparent analysis of the core-to-valence absorption signals, filling gaps in the theoretical understanding of the Br-3d transient absorption spectra.

Subject Categories:

  • Radiation and Nuclear Chemistry
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE