Intramolecular nuclear dynamics in intermolecular Coulombic electron capture

Area of Science:

• Physical Chemistry
• Atomic and Molecular Physics
• Theoretical Chemistry

Background:

• Intermolecular Coulombic electron capture (ICEC) is a process where an electron attaches to one molecule by ionizing a neighboring molecule.
• Previous theoretical models often assumed fixed nuclei, neglecting the significant impact of molecular motion on the ICEC process.

Purpose of the Study:

• To develop an analytical model for ICEC that incorporates the internal nuclear dynamics of the participating molecules.
• To investigate the influence of nuclear motion on ICEC cross sections and electron spectra.

Main Methods:

• Developed an analytical model for ICEC including nuclear dynamics.
• Utilized theoretical vibrationally resolved photoionization cross sections.
• Applied the Franck-Condon principle to account for nuclear motion.

Main Results:

• The model yields electron spectra, vibronic transition-specific ICEC cross sections, and temperature-dependent cross sections.
• Nuclear dynamics distribute the electronic cross section across multiple vibrational states.
• In the H + LiH system, nuclear motion during ICEC triggers LiH dissociation.

Conclusions:

• Internal nuclear motion is crucial for accurately modeling ICEC.
• The developed model provides insights into the vibronic and dynamic aspects of ICEC.
• ICEC can lead to molecular dissociation, particularly when nuclear dynamics are considered.