Influence of vibrational motion and temperature on interatomic Coulombic electron capture

Area of Science:

• Chemical Physics
• Atomic and Molecular Physics
• Quantum Chemistry

Background:

• Interatomic Coulombic electron capture (ICEC) is an environment-mediated electron attachment process.
• Previous theoretical models of ICEC assumed fixed nuclei, neglecting nuclear dynamics.
• Recent studies suggest nuclear motion significantly influences ICEC outcomes.

Purpose of the Study:

• To develop an analytical model incorporating vibrational nuclear motion into ICEC cross-section calculations.
• To investigate the combined effects of energy and electron transfer in ICEC.
• To validate the model by comparing it with fixed-nuclei R-matrix calculations.

Main Methods:

• Development of an analytical model for ICEC cross section that includes vibrational motion.
• Comparison of model results with adiabatic-nuclei approximation based on ab initio R-matrix calculations.
• Application of the theory to the helium-neon dimer system.

Main Results:

• Vibrational dynamics can slightly reduce ICEC efficiency but ICEC remains dominant over photorecombination.
• ICEC process, including nuclear dynamics, can trigger dimer dissociation.
• Accounting for nuclear motion enables description of electron spectrum broadening and temperature-dependent cross sections.

Conclusions:

• Nuclear dynamics play a crucial role in the ICEC process, influencing its efficiency and observable spectra.
• The developed analytical model provides a more comprehensive understanding of ICEC, surpassing fixed-nuclei approaches.
• This work opens avenues for studying temperature-dependent ICEC cross sections and related phenomena.