A photochemical reaction in different theoretical representations

Ibele, Lea M.; Curchod, Basile F.E.; Agostini, Federica

Abstract

The Born–Oppenheimer picture has forged our representation and interpretation of photochemical processes, from photoexcitation down to the passage through a conical intersection, a funnel connecting different electronic states. In this work, we analyze a full in silico photochemical experiment, from the explicit electronic excitation by a laser pulse to the formation of photoproducts following a nonradiative decay through a conical intersection, by contrasting the picture offered by Born–Oppenheimer and that proposed by the exact factorization. The exact factorization offers an alternative understanding of photochemistry that does not rely on concepts such as electronic states, nonadiabatic couplings, and conical intersections. On the basis of nonadiabatic quantum dynamics performed for a two-state 2D model system, this work allows us to compare Born–Oppenheimer and exact factorization for (i) an explicit photoexcitation with and without the Condon approximation, (ii) the passage of a nuclear wavepacket through a conical intersection, (iii) the formation of excited stationary states in the Franck–Condon region, and (iv) the use of classical and quantum trajectories in the exact factorization picture to capture nonadiabatic processes triggered by a laser pulse.

Citation

Ibele, L. M., Curchod, B. F., & Agostini, F. (2022). A photochemical reaction in different theoretical representations. The Journal of Physical Chemistry A, 126(7), 1263-1281. https://doi.org/10.1021/acs.jpca.1c09604

• Journal Article Type: Article
• Online Publication Date: Feb 14, 2022
• Publication Date: Feb 24, 2022
• Deposit Date: Jan 31, 2022
• Publicly Available Date: May 25, 2022
• Journal: Journal of Physical Chemistry A
• Print ISSN: 1089-5639
• Electronic ISSN: 1520-5215
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 126
• Issue: 7
• Pages: 1263-1281
• DOI: https://doi.org/10.1021/acs.jpca.1c09604