Monitoring Non-adiabatic Dynamics in CS2 with Time- and Energy-Resolved Photoelectron Spectra of Wavepackets

Monitoring Non-adiabatic Dynamics in CS2 with Time- and Energy-Resolved Photoelectron Spectra of Wavepackets

Feb. 2017 – New article in Chemical Physics Letters:

Monitoring Non-adiabatic Dynamics in CS2 with Time- and Energy-Resolved Photoelectron Spectra of Wavepackets

Kwanghsi Wang(a) Vincent McKoy(a)Paul Hockett(b)Albert Stolow(b, c, d),Michael S. Schuurman(b, d),

a A. A. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA

b National Research Council Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada

c Department of Physics, University of Ottawa, ON K1N 6N5 Canada

d Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON, K1N 6N5, Canada

Highlights

• Time-resolved photoelectron angular distributions around conical intersections are studied.
• Ab initio multiple spawning method is applied to obtain wavepacket densities.
• Geometry and energy dependent photoelectron matrix elements are employed.
• Molecular and laboratory photoelectron angular distributions are used to illustrate the non-adiabatic dynamics.
• Photoelectron spectra are compared with measured values.

Abstract

We report results from a novel fully ab initio method for simulating the time-resolved photoelectron angular distributions around conical intersections in CS2. The technique employs wavepacket densities obtained with the multiple spawning method in conjunction with geometry- and energy-dependent photoionization matrix elements. The robust agreement of the calculated molecular-frame photoelectron angular distributions with measured values for CS2 demonstrates that this approach can successfully illuminate, and disentangle, the underlying coupled nuclear and electronic dynamics around conical intersections in polyatomic molecules.

DOI: 10.1016/j.cplett.2017.02.014

Wigner delays in molecular ionization

Wigner delays in molecular ionization

A snippet from some theory work in progress on time delays in molecular photoionization. The image below shows the energy and angle-resolved cross-section (surface topography) and Wigner delay (colour map) over a 40 eV range for CO. Unsurprisingly, for a molecular scatterer (albeit a simple heteronuclear diatomic) the map is quite complicated! Here the delays range from -200 to +200 attoseconds, and peak at the Carbon end of the molecule.

Wigner delays in CO

More on this soon… the paper is almost ready…

 

UPDATE Dec. 2015

Now on the arXiv:

Time Delay in Molecular Photoionization

P. Hockett, E. Frumker, D.M. Villeneuve, P.B. Corkum

arXiv 1512.03788, 2015