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Title: Monitoring nonadiabatic avoided crossing dynamics in molecules by ultrafast X-ray diffraction

We examine time-resolved X-ray diffraction from molecules in the gas phase which undergo nonadiabatic avoided-crossing dynamics involving strongly coupled electrons and nuclei. Several contributions to the signal are identified, representing (in decreasing strength) elastic scattering, contributions of the electronic coherences created by nonadiabatic couplings in the avoided crossing regime, and inelastic scattering. The former probes the charge density and delivers direct information on the evolving molecular geometry. The latter two contributions are weaker and carry spatial information through the transition charge densities (off-diagonal elements of the charge-density operator). Furthermore, simulations are presented for the nonadiabatic harpooning process in the excited state of sodium fluoride.
 [1] ;  [2] ;  [2]
  1. Univ. of California, Irvine, CA (United States). Chemistry Dept.
  2. Univ. of California, Irvine, CA (United States). Chemistry Dept. and Dept. of Physics and Astronomy
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Structural Dynamics
Additional Journal Information:
Journal Volume: 4; Journal Issue: 5; Journal ID: ISSN 2329-7778
American Crystallographic Association/AIP
Research Org:
Univ. of California, Irvine, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; Alexander von Humboldt Foundation (Germany)
Country of Publication:
United States
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; materials; scattering; electrical conductivity; continuum mechanics; metals; diffraction optics; condensed matter electronic structure; condensed matter properties; electrical properties; signal processing
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1361914