Computational Molecular Electronic Spectroscopy with TD-DFT.

Area of Science:

• Computational Chemistry
• Quantum Chemistry
• Spectroscopy

Background:

• Accurately predicting molecular optical signatures is crucial for understanding material properties.
• Traditional methods often rely on approximations that limit their predictive power for complex systems.

Purpose of the Study:

• To present applications of Time-Dependent Density Functional Theory (TD-DFT) for reproducing and rationalizing optical signatures.
• To focus on calculations that go beyond the vertical approximation, specifically 0-0 energies and vibronic spectra.
• To showcase large-scale applications for real-life organic and inorganic structures.

Main Methods:

• Utilizing TD-DFT to compute absorption and fluorescence spectra.
• Performing calculations beyond the vertical approximation to determine 0-0 energies and vibronic spectra.
• Benchmarking various exchange-correlation functionals within the TD-DFT framework.

Main Results:

• Demonstrated successful reproduction and rationalization of optical signatures for conjugated organic and inorganic compounds.
• Presented calculations of 0-0 energies and vibronic spectra, offering deeper insights into molecular transitions.
• Showcased applications in areas such as organic/inorganic dyes, charge-transfer structures, and excited-state proton transfer.

Conclusions:

• TD-DFT is a powerful tool for predicting and understanding molecular optical properties.
• Moving beyond the vertical approximation enhances the accuracy of spectral predictions.
• The choice of exchange-correlation functional significantly impacts TD-DFT performance, necessitating careful benchmarking.