Cartesian coupled coherent states simulations: Ne(n)Br2 dissociation as a test case

Area of Science:

• Chemical Physics
• Quantum Dynamics
• Spectroscopy

Background:

• Vibrational predissociation is a key decay pathway for weakly bound molecular complexes.
• Accurate theoretical methods are needed to understand dissociation dynamics and predict lifetimes.

Purpose of the Study:

• To describe and validate the coupled coherent states (CCS) simulation method for vibrational predissociation.
• To assess the applicability of CCS to larger molecular clusters.

Main Methods:

• Implementation of the CCS method in the Cartesian frame, analogous to classical molecular dynamics.
• Simulation of vibrational predissociation in Ne-Br2(ν) complexes.

Main Results:

• Calculated lifetimes for Ne-Br2(ν) complexes show excellent agreement with experimental data and prior theoretical results.
• The CCS method, while quantum, exhibits semiclassical behavior at longer times, impacting convergence of certain properties.
• Preliminary results demonstrate the method's potential for analyzing larger tetra- and penta-atomic clusters.

Conclusions:

• The CCS method provides a reliable approach for calculating vibrational predissociation lifetimes of weakly bound complexes.
• The CCS technique is adaptable for studying the dynamics of larger molecular systems, offering insights into cluster dissociation.
• Further development may address challenges in converging fully quantum aspects for complex systems.