Electron transfer mediated decay in HeLi₂ cluster: Potential energy surfaces and decay widths

Area of Science:

• Atomic and Molecular Physics
• Quantum Chemistry
• Surface Science

Background:

• Electron transfer mediated decay (ETMD) causes double ionization of dopants in helium droplets.
• ETMD is initiated by He+ neutralization, significantly increasing dopant double ionization cross sections.
• Nuclear dynamics during ETMD influence decay efficiency, secondary electron spectra, and ionic product characteristics.

Purpose of the Study:

• To theoretically investigate multimode nuclear dynamics accompanying ETMD in a helium droplet environment.
• To establish a minimal theoretical model (He-Li2 cluster) for studying ETMD dynamics relevant to experimental systems.
• To analyze the influence of the dopant's electronic state (Li2 ground and excited states) on ETMD.

Main Methods:

• Ab initio calculations of potential energy surfaces for the He-Li2 cluster electronic states involved in ETMD.
• Calculation of decay widths for the relevant electronic states.
• Examination of multimode nuclear dynamics during the electronic decay process.

Main Results:

• Ab initio potential energy surfaces and decay widths for the He-Li2 cluster were computed.
• The structure of potential energy surfaces and nuclear dynamics are strongly dependent on the electronic state of Li2.
• The electronic structure of the dopant dictates the overall decay rate and observable electron spectra.

Conclusions:

• The study presents the first theoretical investigation of multimode dynamics during ETMD in a helium droplet model system.
• Findings highlight the crucial role of the dopant's electronic state in determining ETMD characteristics.
• The He-Li2 cluster serves as a viable model for understanding ETMD in experimental settings like Li2 on helium droplets.