Combining the Bethe–Salpeter Formalism with Time-Dependent DFT Excited-State Forces to Describe Optical Signatures: NBO Fluoroborates as Working Examples

International audienceWe 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