title: The structure of the O2-N2O complex.
abstract: We 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.
authors.affiliation: School of Science, Faculty of Science and Engineering, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Salmon
authors.affiliation: School of Science, Faculty of Science and Engineering, University of Waikato, Private Bag 3105, Hamilton 3240, New Zealand.
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Lane