Virtual photon exchange vs electron transfer in interparticle Coulombic electron capture.

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Computational Chemistry

Background:

• Interparticle Coulombic Electron Capture (ICEC) is a key process in ion-molecule interactions.
• Understanding ICEC is crucial for modeling chemical reactions and energy transfer in various environments.

Purpose of the Study:

• To investigate the contributions of virtual photon exchange and electron transfer to ICEC.
• To analyze the impact of molecular orientation on ICEC cross sections.
• To explore the role of projectile charge in ICEC processes.

Main Methods:

• Ab initio calculations were performed for H+ + H2O and H + H2O+ systems.
• The study analyzed the dependence of ICEC cross sections on interparticle distance.
• Positron collisions were simulated to study projectile charge effects.

Main Results:

• Both virtual photon exchange and electron transfer contribute to the total ICEC cross section.
• Molecular orientation significantly affects ICEC cross sections, by up to two orders of magnitude at small distances.
• Electron transfer is confirmed in positron collisions, with projectile charge influencing the process at low energies.

Conclusions:

• The relative orientation of interacting particles is a critical factor in ICEC.
• The contributions of different mechanisms to ICEC vary depending on the specific system.
• Projectile charge plays a notable role in ICEC, particularly at low collision energies.