Skip to main content

Research Repository

Advanced Search

Fast vibrational calculation of anharmonic OH-stretch frequencies for two low-energy noradrenaline conformers

Benoit, David M.

Authors

Profile image of David Benoit

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



Abstract

We introduce a new reduced-coupling technique to accelerate direct calculations of a selected number of vibrational frequencies in large molecular systems. Our method combines the advantages of the single-to-all correlation-corrected vibrational self-consistent field (STA-CC-VSCF) approach [D. M. Benoit, J. Chem. Phys. 125, 244110 (2006)] with those of the fast-CC-VSCF technique [D. M. Benoit, J. Chem. Phys. 120, 562 (2004)] and allows the ab initio calculation of only the relevant parts of the required potential energy surface (PES). We demonstrate, using a set of five aliphatic alcohol molecules, that the new fast-STA-CC-VSCF method is accurate and leads to very substantial time gains for the computations of the PES. We then use the fast-STA-CC-VSCF method to accelerate the computation of the OH-stretch and NH-stretch frequencies of the two lowest-energy conformers of noradrenaline, namely, AG1a and GG1a. Our new approach enables us to run the calculation 89 times faster than the standard CC-VSCF technique and makes it possible to use a high-level MP2/TZP description of the PES. We demonstrate that the influence of the strong mode-mode couplings is crucial for a realistic description of the particular OH-stretch vibrational signature of each conformer. Finally, of the two possible low-energy conformers, we identify AG1a as the one most likely to have been observed in the experiments of Snoek [Mol. Phys. 101, 1239 (2003)].

Citation

Benoit, D. M. (2008). Fast vibrational calculation of anharmonic OH-stretch frequencies for two low-energy noradrenaline conformers. The Journal of chemical physics, 129(23), Article 234304. https://doi.org/10.1063/1.3040427

Journal Article Type Article
Acceptance Date Nov 1, 2008
Online Publication Date Dec 16, 2008
Publication Date Dec 21, 2008
Deposit Date Nov 13, 2014
Publicly Available Date Nov 13, 2014
Journal Journal of chemical physics
Print ISSN 0021-9606
Publisher American Institute of Physics
Peer Reviewed Peer Reviewed
Volume 129
Issue 23
Article Number 234304
DOI https://doi.org/10.1063/1.3040427
Keywords Physical and Theoretical Chemistry; General Physics and Astronomy
Public URL https://hull-repository.worktribe.com/output/462184
Publisher URL http://scitation.aip.org/content/aip/journal/jcp/129/23/10.1063/1.3040427
Additional Information Copy of article: Fast vibrational calculation of anharmonic OH-stretch frequencies for two low-energy noradrenaline conformers Benoit, David M., The Journal of Chemical Physics, 129, 234304 (2008), DOI:http://dx.doi.org/10.1063/1.3040427
Contract Date Nov 13, 2014

Files

Published article.pdf (503 Kb)
PDF

Copyright Statement
© 2008 American Institute of Physics






You might also like



Downloadable Citations