Intramolecular quantum dynamics on intersecting potential energy surfaces: a tutorial review

Area of Science:

• Chemical Physics
• Quantum Chemistry
• Spectroscopy

Background:

• Vibronic coupling is a key phenomenon influencing molecular electronic spectra and excited-state dynamics.
• The Born-Oppenheimer approximation, separating electronic and nuclear motion, is a foundational concept but has limitations.
• Understanding these limitations is crucial for accurately describing molecular behavior.

Purpose of the Study:

• To provide a clear overview of the fundamental principles of vibronic coupling.
• To illustrate basic concepts with relevant examples.
• To offer insights for both beginners and experts in the field.

Main Methods:

• Review of fundamental concepts in vibronic coupling.
• Discussion of the Born-Oppenheimer approximation and its limitations.
• Inclusion of illustrative examples from molecular spectroscopy and dynamics.

Main Results:

• The review elucidates the ubiquitous nature of vibronic coupling in molecular systems.
• It highlights the limitations of the strict Born-Oppenheimer separation.
• Key aspects of vibronic coupling are presented with practical examples.

Conclusions:

• Vibronic coupling significantly impacts molecular electronic spectra and dynamics.
• A deeper understanding beyond the Born-Oppenheimer approximation is often necessary.
• This review serves as a valuable resource for studying vibronic coupling.