Phys. Rev. Lett. 120, 163002 – Published 16 April 2018
The hydrogen molecule has become a test ground for quantum electrodynamical calculations in molecules. Expanding beyond studies on stable hydrogenic species to the heavier radioactive tritium-bearing molecules, we report on a measurement of the fundamental T2 vibrational splitting (v=0→1) for J=0–5 rotational levels. Precision frequency metrology is performed with high-resolution coherent anti-Stokes Raman spectroscopy at an experimental uncertainty of 10–12 MHz, where sub-Doppler saturation features are exploited for the strongest transition. The achieved accuracy corresponds to a 50-fold improvement over a previous measurement, and it allows for the extraction of relativistic and QED contributions to T2 transition energies.
Feb. 2017 – New article in Chemical Physics Letters:
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
- • 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.
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.