Low-energy electron collisions with glycine

Area of Science:

• Computational Chemistry
• Atomic and Molecular Physics
• Quantum Chemistry

Background:

• Electron scattering experiments provide insights into molecular electronic structures.
• Glycine, the simplest amino acid, is a fundamental molecule in biological systems.
• Understanding electron interactions with glycine is crucial for various chemical and biological processes.

Purpose of the Study:

• To calculate elastic electron scattering cross sections for gas-phase glycine.
• To investigate the presence and energies of shape resonances in glycine.
• To explore potential mechanisms for dissociative electron attachment to glycine.

Main Methods:

• Schwinger multichannel method with parallelization and pseudopotentials.
• Calculation of cross sections for elastic electron scattering.
• Analysis of eigenphase sums to identify resonance states.

Main Results:

• Identified a π* shape resonance between 2.3 eV and 2.8 eV, consistent with experimental data for the most stable isomer.
• Located a shape resonance near 9.5 eV in the A' symmetry, potentially coupled to hydroxyl group vibrations.
• Did not find definitive signatures of a shape resonance around 4 eV, despite investigating stretched OH bond lengths.

Conclusions:

• The new computational implementation provides reliable cross sections for electron scattering on glycine.
• Resonance structures provide valuable data for understanding electron-molecule interactions and potential reaction pathways.
• Further investigation may be needed to fully elucidate low-energy electron attachment mechanisms involving the OH bond.