Combining the Bethe–Salpeter Formalism with Time-Dependent DFT Excited-State Forces to Describe Optical Signatures: NBO Fluoroborates as Working Examples
Résumé
We propose to use a blend of methodologies to tackle a challenging case for quantum approaches: the simulation of the optical properties of asym. fluoroborate derivs. Indeed, these dyes, which present a low-lying excited-state exhibiting a cyanine-like nature, are treated not only with the Time-Dependent D. Functional Theory (TD-DFT) method to det. both the structures and vibrational patterns but also with the Bethe-Salpeter approach to compute both the vertical absorption and emission energies. This combination allows us to obtain 0-0 energies with a significantly improved accuracy compared to the "raw" TD-DFT ests. We also discuss the impact of various declinations of the Polarizable Continuum Model (linear-response, cor. linear-response, and state-specific models) on the obtained accuracy.