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Analysis of vibrational autoionization of CaF Rydberg states
Jun Jiang1, Timothy J Barnum1, Stephen L Coy1
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
The Journal of Chemical Physics
|April 22, 2019
Summary
Calculations reveal the n.36 p^Π Rydberg series in CaF exhibits the fastest vibrational autoionization rates. This is explained by l-uncoupling and a valence-precursor model, linking Rydberg electron density to autoionization.
Area of Science:
- * Molecular Spectroscopy
- * Quantum Defect Theory
- * Rydberg States
Background:
- * Vibrational autoionization is a key decay process for Rydberg states.
- * Understanding electron-ion core interactions is crucial for predicting molecular behavior.
- * Previous studies lacked detailed mechanistic insights into CaF Rydberg state autoionization.
Purpose of the Study:
- * To calculate vibrational autoionization rates for CaF Rydberg states using multi-channel quantum defect theory (MQDT).
- * To interpret MQDT results using physical models, focusing on Rydberg electron-ion core interactions.
- * To characterize the mechanisms governing vibrational autoionization in CaF.
Main Methods:
- * Global multi-channel quantum defect theory (MQDT) fitting.
- * Application of intuitive physical models (l-uncoupling, valence-precursor model).
- * Ligand-field model analysis of valence-precursor states.
Main Results:
- * The n.36 p^Π Rydberg series shows significantly faster Δv = 1 vibrational autoionization rates compared to other core-penetrating series.
- * Rotational level dependence of autoionization rates is explained by l-uncoupling interactions.
- * The valence-precursor model successfully interprets the relative autoionization rates of six core-penetrating Rydberg series.
Conclusions:
- * The n.36 p^Π series' enhanced autoionization rate is attributed to specific l-uncoupling effects.
- * The valence-precursor model provides a framework for understanding autoionization mechanisms in CaF Rydberg states.
- * Electronic properties of valence-precursor states correlate with vibrational autoionization rates, highlighting the role of electron density.
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