Monitoring Nonadiabatic Avoided Crossing Dynamics in Molecules by Ultrafast X-Ray Diffraction

Abstract

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 of the transition charge densities (off-diagonal elements of the charge-density operator). Simulations are presented for the nonadiabatic harpooning process in the excited states of sodium fluoride.

References in corpus (6)

• Imaging electronic quantum motion with light
• Diffractive Imaging of Coherent Nuclear Motion in Isolated Molecules
• Self-referenced coherent diffraction x-ray movie of Angstrom- and femtosecond-scale atomic motion
• Radiation Generated by Charge Migration Following Ionization
• Monitoring Nonadiabatic Electron-Nuclear Dynamics in Molecules by Attosecond Streaking of Photoelectrons
• Time-, Frequency-, and Wavevector-Resolved X-Ray Diffraction from Single Molecules