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

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.

Citation

Wong, S. Y. Y., Benoit, D. M., Lewerenz, M., Brown, A., & Roy, P.-N. (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), Article 094110. https://doi.org/10.1063/1.3553179

• Journal Article Type: Article
• Acceptance Date: Jan 1, 2011
• Online Publication Date: Mar 3, 2011
• Publication Date: Mar 3, 2011
• Journal: JOURNAL OF CHEMICAL PHYSICS
• Print ISSN: 0021-9606
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 134
• Issue: 9
• Article Number: 094110
• DOI: https://doi.org/10.1063/1.3553179
• Keywords: Self-consistent-field; Time-correlation-functions; Herman-Kluk propagator; Dynamics approximation
• Public URL: https://hull-repository.worktribe.com/output/399984
• Publisher URL: https://aip.scitation.org/doi/10.1063/1.3553179