Related Experiment Video
Updated: Sep 21, 2025
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Line Shape Analysis of Dynamic NMR Spectra for Characterizing Coordination Sphere Rearrangements at a Chiral Rhenium Polyhydride Complex
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Projected Complex Absorbing Potential Multireference Configuration Interaction Approach for Shape and Feshbach
Mushir Thodika1, Spiridoula Matsika1
1Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, United States.
Journal of Chemical Theory and Computation
|May 27, 2022
Summary
Computational chemists can now accurately characterize anion resonances, including complex two-particle one-hole types, using a new multireference configuration interaction method with a projected complex absorbing potential.
Area of Science:
- Quantum Chemistry
- Theoretical Chemistry
- Chemical Physics
Background:
- Anion resonances are transient states in electron-molecule collisions, challenging to model due to their short lifetimes.
- Standard quantum chemistry methods struggle with accurately describing two-particle one-hole (2p-1h) resonances and their interactions.
Purpose of the Study:
- To develop and validate a computational method for characterizing both single-particle and 2p-1h anion resonances.
- To accurately describe the coupling between different types of resonances, particularly Feshbach and shape resonances.
Main Methods:
- Implementation of a projected complex absorbing potential (CAP) within the multireference configuration interaction (MRCI) framework.
- Application of the projected-CAP-MRCI method to N2-, H2O-, and dicyanoethylene isomers.
Main Results:
- The projected-CAP-MRCI method successfully characterized the 2Πg shape resonance in N2-.
- Smooth complex potential energy surfaces were obtained for shape resonances.
- The method efficiently captured the mixing between Feshbach and shape resonances in dicyanoethylene anions, impacting their lifetimes.
Conclusions:
- The projected-CAP-MRCI approach provides an accurate and versatile tool for studying anion resonances.
- This method is particularly valuable for understanding complex resonance phenomena like Feshbach resonances and resonance mixing.
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