Cavity-modified local and non-local electronic interactions in molecular ensembles under vibrational strong coupling

Area of Science:

• Quantum Chemistry
• Physical Chemistry
• Spectroscopy

Background:

• Vibrational strong coupling (VSC) is key to vibro-polaritonic chemistry, linking molecular vibrations and optical cavity modes.
• Understanding nonresonant electron-photon interactions is crucial for predicting cavity effects on molecular systems.
• Existing theories often neglect these complementary interactions in cavity-based chemistry.

Purpose of the Study:

• To theoretically investigate the role of nonresonant electron-photon interactions in the cavity Born-Oppenheimer (CBO) approximation.
• To study how VSC modifies local and non-local electronic interactions in molecular ensembles within optical cavities.
• To introduce and analyze the cavity reaction potential (CRP) for vibro-polaritonic reaction mechanisms.

Main Methods:

• Combined CBO perturbation theory (CBO-PT) with non-perturbative CBO Hartree-Fock (HF) and coupled cluster (CC) theories.
• Derived second-order CBO-PT cavity potential energy surfaces and cavity reaction potentials (CRPs).
• Applied CBO-HF and CBO-CC approaches to unimolecular and bimolecular systems.

Main Results:

• Cavity-induced corrections to intra- and inter-molecular interactions were identified.
• Unimolecular reactions showed minor modifications to potential energy surfaces, primarily from dipole fluctuation corrections.
• Bimolecular systems exhibited enhanced long-range, cavity-polarization-dependent interactions and explicit coupling to cavity modes.

Conclusions:

• Nonresonant electron-photon interactions significantly modify molecular interactions under VSC.
• The CRP concept provides a framework for understanding vibro-polaritonic reaction mechanisms.
• The study offers a comprehensive theoretical approach to cavity-modified molecular dynamics.