Photoelectron angular distributions from O K shell of oriented CO molecules: A critical comparison between theory and
1Photon Factory, Institute of Materials Structure Science, Oho 1-1, Tsukuba-shi, Ibaraki-ken 305-0801, Japan.
Physical Review Letters
|September 16, 2000
Summary
Photoelectron spectroscopy of oriented carbon monoxide (CO) molecules reveals significant contributions from multiple partial waves to a sigma(*) shape resonance. Further theoretical advancements are needed for precise agreement with experimental data.
Area of Science:
- Molecular physics
- Quantum chemistry
- Photoelectron spectroscopy
Background:
- Understanding molecular photoionization dynamics is crucial for various fields.
- Shape resonances significantly influence photoionization processes.
- Oriented molecules provide detailed insights into electron emission anisotropy.
Purpose of the Study:
- To experimentally determine the dynamical information of O K-shell photoionization in oriented CO molecules.
- To investigate the contributions of different partial waves to a sigma(*) shape resonance.
- To compare experimental results with theoretical calculations.
Main Methods:
- Measuring angular distributions of photoelectrons from oriented CO molecules.
- Utilizing light polarization parallel and perpendicular to the molecular axis.
- Analyzing photoelectron spectra near the ionization threshold.
Main Results:
- Deduced ten dipole matrix elements and eight phase differences.
- Demonstrated a significant contribution of six lsigma partial waves (0 ≤ l ≤ 5) to the sigma(*) shape resonance.
- Observed only qualitative agreement between experimental data and relaxed core Hartree-Fock calculations.
Conclusions:
- The sigma(*) shape resonance in CO O K-shell photoionization is complex, involving multiple partial waves.
- Current theoretical models, such as relaxed core Hartree-Fock, are insufficient for quantitative predictions.
- More advanced theoretical approaches are required to accurately describe the observed dynamics.
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