Nonequilibrium quantum solvation with a time-dependent Onsager cavity

Area of Science:

• Quantum chemistry
• Theoretical chemistry
• Chemical physics

Background:

• Understanding solvation dynamics is crucial for chemical reactions.
• Nonequilibrium solvation effects are important in dynamic processes.
• Quantum effects in solvation are increasingly studied.

Purpose of the Study:

• To formulate a theory of nonequilibrium quantum solvation with time-dependent solvent parameters.
• To analyze the relaxation properties of a test molecular point dipole in a dielectric solvent with dynamic boundary conditions.
• To investigate the impact of shrinking and breathing Onsager cavities on dipole relaxation.

Main Methods:

• Formulation of a quantum solvation theory.
• Modeling the solvent as a spherical Onsager cavity with time-dependent radius.
• Analysis of a test molecular point dipole's response function.
• Consideration of shrinking and breathing cavity dynamics.

Main Results:

• Time-dependent solvent parameters lead to a time-dependent frequency-dependent response function.
• A shrinking Onsager sphere generally enhances dipole relaxation, increasing the linewidth.
• A breathing Onsager sphere can reduce damping, with resonant suppression when breathing and relaxation rates are comparable.
• The linewidth is significantly reduced when the breathing sphere reaches its maximum extension.

Conclusions:

• Nonequilibrium quantum solvation theory provides insights into dynamic solvent effects.
• Time-dependent cavity dynamics significantly alter molecular dipole relaxation.
• The breathing Onsager sphere model offers a pathway to control and suppress damping in quantum systems.