Role of the Electron-Dipole Interaction in Photodetachment Angular Distributions

Area of Science:

• Chemical Physics
• Atomic and Molecular Physics
• Quantum Chemistry

Background:

• Photodetachment and photoionization processes are fundamental in atomic and molecular physics.
• Accurate theoretical models are needed to explain experimental observations near threshold.
• The role of long-range electron-molecule interactions is often simplified or neglected.

Purpose of the Study:

• To demonstrate the importance of long-range electron-molecule interactions in photodetachment.
• To investigate the near-threshold photodetachment of cyanide anion (CN-).
• To explain the observed behavior of the photodetachment cross section near threshold.

Main Methods:

• Combined experimental and computational approach.
• Photoelectron imaging for measuring near-threshold anisotropy parameters (β).
• Calculation of β values using EOM-IP-CCSD/aug-cc-pVTZ Dyson orbitals with free-particle and point dipole models.

Main Results:

• Measured near-threshold anisotropy parameters (β) for CN- detachment.
• Calculated β values show the influence of the molecular dipole moment.
• The study provides an explanation for the recently reported near-threshold behavior of the photodetachment cross section.

Conclusions:

• Long-range electron-molecule interactions significantly impact photodetachment dynamics.
• The molecular dipole moment plays a critical role in near-threshold detachment.
• Accurate theoretical treatments must incorporate these interactions for quantitative agreement with experiments.