Nonadiabatic Dynamics: Method Development and Applications

DIPC Seminars

Speaker

Edison Salazar
DIPC

When

2025/11/13
10:00

Place

Faculty of Chemistry, Salón de Actos

Host

Mario Piris

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Kimika Teorikoa Seminar

Photochemical reactions are commonly investigated using nonadiabatic dynamics, with Tully’s trajectory surface hopping (TSH) algorithm being the most widely employed approach [1]. This algorithm requires the evaluation of electronic energies, gradients, and nonadiabatic couplings between the involved electronic states at each timestep. These quantities are typically obtained from
multiconfigurational methods, which, while accurate, exhibit an exponential scaling with respect to the size of the active space—restricting their application to small molecular systems.
To overcome this limitation, alternative methods such as spin-flip time-dependent density functional theory (SF-TDDFT) have demonstrated an effective balance between computational cost and accuracy. More recently, the advent
of quantum computing has opened new avenues for electronic structure calculations. Quantum algorithms such as the state-averaged orbital-optimized variational quantum eigensolver (SA-OO-VQE) offer promising strategies to
obtain electronic structure parameters suitable for nonadiabatic dynamics, particularly in the Noisy Intermediate-Scale Quantum (NISQ) era.
In this seminar, we present the photorelaxation processes of a set of test molecular systems, the implementation of a TSH-based framework integrated into the PySurf package [2], and results obtained using SF-TDDFT and SA-OO-
VQE. Additionally, we show preliminary results employing the natural orbital functional VQE (NOFVQE) in combination with PySurf to perform direct dynamics.

[1] J. C. Tully, J. Chem. Phys. 93, 1061 (1990).
[2] E. X. Salazar, M. F. S. J. Menger, and S. Faraji, J. Chem. Theory Comput., 2024, 20, 5796–5806