Interference between Multiple Photoionization Pathways in Chiral Molecules: Converging Continuum Results in Gaussian Bases.

This study focuses on the photoionization dynamics of chiral molecules. Our group has recently shown that the RABBITT (Reconstruction of Attosecond Beating by Interference of Two-photon Transitions) technique can be useful in measuring and understanding photoelectron circular dichroism (PECD) in randomly oriented chiral molecules [1][2]. PECD is a photoelectron asymmetry unique to these molecules. In this study, we address the challenge of explaining the continuum dynamics using a standard quantum chemistry basis set. Quantum chemistry basis sets are based on Gaussian functions, which are designed and optimized to accurately describe electron behavior in bound systems where electrons are localized around atoms or molecules. However, they lack precision and accuracy when it comes to representing electron density in a continuous regime. We employ time-dependent perturbation theory to determine PECD and show the significance of addressing continuum interactions within molecules by augmenting correlation-consistent quantum chemistry basis sets with large diffuse functions. The results show the convergence (and in some cases non-convergence) of PECD with diffuse functions.

[1] R. Esteban Goetz, Christiane P. Koch, and Loren Greenman Phys. Rev. Lett. 122, 013204 (2019)

[2] arXiv:2104.07522v2 [physics.atom-ph]