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Determination of molecular vibrational state energies using the ab initio semiclassical initial value representation: application to formaldehyde

Wong, Stephanie Y. Y.; Benoit, David M.; Lewerenz, Marius; Brown, Alex; Roy, Pierre-Nicholas

Authors

Stephanie Y. Y. Wong

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Dr David Benoit D.Benoit@hull.ac.uk
Senior Lecturer in Molecular Physics and Astrochemistry

Marius Lewerenz

Alex Brown

Pierre-Nicholas Roy



Abstract

We have demonstrated the use of ab initio molecular dynamics (AIMD) trajectories to compute the vibrational energy levels of molecular systems in the context of the semiclassical initial value representation (SC-IVR). A relatively low level of electronic structure theory (HF/3-21G) was used in this proof-of-principle study. Formaldehyde was used as a test case for the determination of accurate excited vibrational states. The AIMD-SC-IVR vibrational energies have been compared to those from curvilinear and rectilinear vibrational self-consistent field/vibrational configuration interaction with perturbation selected interactions-second-order perturbation theory (VSCF/VCIPSI-PT2) and correlation-corrected vibrational self-consistent field (cc-VSCF) methods. The survival amplitudes were obtained from selecting different reference wavefunctions using only a single set of molecular dynamics trajectories. We conclude that our approach is a further step in making the SC-IVR method a practical tool for first-principles quantum dynamics simulations.

Journal Article Type Article
Publication Date Mar 3, 2011
Journal JOURNAL OF CHEMICAL PHYSICS
Print ISSN 0021-9606
Electronic ISSN 1089-7690
Publisher AIP Publishing
Peer Reviewed Peer Reviewed
Volume 134
Issue 9
Article Number 094110
APA6 Citation Wong, S. Y. Y., Benoit, D. M., Lewerenz, M., Brown, A., & Roy, P. (2011). Determination of molecular vibrational state energies using the ab initio semiclassical initial value representation: application to formaldehyde. The Journal of chemical physics, 134(9), https://doi.org/10.1063/1.3553179
DOI https://doi.org/10.1063/1.3553179
Keywords Self-consistent-field; Time-correlation-functions; Herman-Kluk propagator; Dynamics approximation
Publisher URL https://aip.scitation.org/doi/10.1063/1.3553179