Assessing surface hopping methods for long-time internal conversion dynamics: The case of lutein

Surface hopping methods, such as fewest switches surface hopping (FSSH), are widely used to simulate ultrafast nonadiabatic phenomena. However, their accuracy in capturing long-time nonadiabatic dynamics remains largely untested. Here, we assess and compare several surface hopping approaches for describing long-timescale nonadiabatic dynamics, using the S1 → S0 internal conversion of the carotenoid lutein in vacuum and in solution as a test case. Our simulations show that the commonly used FSSH with energy-based decoherence-correction (FSSH-EDC) and our recently proposed semi-focused mapping approach to surface hopping (SMASH) fail to accurately describe the slow internal conversion of lutein. In contrast, two surface hopping variants introduced in this work, namely an adapted FSSH-EDC scheme (A-EDC) and a decoherence-corrected SMASH method (SMASH-DEC), effectively improve the treatment of decoherence effects, compared to their parent methods, and predict S1 → S0 decay times in significantly better agreement with experimental spectroscopic data and more consistent with ab initio multiple spawning (AIMS) simulations.