Toward Accurate Computational Photochemistry, Photophysics, and Spectroscopy of Organic Chromophores

Computational simulations of light-induced events in photoactive molecular materials now provide a detailed description of the molecular motions and mechanisms underlying the reactivity of organic and bio-organic chromophores. In parallel, simulating transient non-linear spectral signals across different spectral regimes (NIR-VIS-UV-X-ray) has advanced significantly in recent years, establishing it as an essential tool for interpreting experimental spectra. As a result, various computational strategies and tools can now be operated as a "virtual spectrometer" to characterize and understand a dye's photoinduced molecular deformation and reactivity. This allows for an accurate description of photochemical and photobiological processes and a rationalization of the corresponding photophysical properties, including those probed by multi-pulse, time-resolved spectroscopy.

This contribution reviews recent advances in computational photochemistry, photophysics, and spectroscopy, spanning both quantum-classical and pure quantum approaches. Methodological developments and their applications—including novel control strategies that exploit the quantum nature of conical intersections—will be illustrated through prototypical (bio)organic chromophores as paradigmatic test cases [1–5].