Salmon, Steven RayLane, Joseph R.2015-11-022015-09-282015-11-022015-09-28Salmon, S. R., & Lane, J. R. (2015). The structure of the O₂-N₂O complex. Journal of Chemical Physics, 143(12). http://doi.org/10.1063/1.49316290021-9606https://hdl.handle.net/10289/9703We have investigated the lowest energy structures and interaction energies of the oxygen nitrous oxide complex (O₂–N₂O) using explicitly correlated coupled cluster theory. We find that the intermolecular potential energy surface of O₂–N₂O is very flat, with two minima of comparable energy separated by a low energy first order saddle point. Our results are able to conclusively distinguish between the two sets of experimental geometric parameters for O₂–N₂O that were previously determined from rotationally resolved infrared spectra. The global minimum structure of O₂–N₂O is therefore found to be planar with a distorted slipped parallel structure. Finally, we show that the very flat potential energy surface of O₂–N₂O is problematic when evaluating vibrational frequencies with a numerical Hessian and that consideration should be given as to whether results might change if the step-size is varied.application/pdfenThis article is published in the Journal of Chemical Physics. © 2015 AIP Publishing LLC.Journal Article10.1063/1.4931629