title: Protonated nitrous oxide, NNOH+: fundamental vibrational frequencies and spectroscopic constants from quartic force fields.
abstract: The interstellar presence of protonated nitrous oxide has been suspected for some time. Using established high-accuracy quantum chemical techniques, spectroscopic constants and fundamental vibrational frequencies are provided for the lower energy O-protonated isomer of this cation and its deuterated isotopologue. The vibrationally-averaged B0 and C0 rotational constants are within 6 MHz of their experimental values and the D(J) quartic distortion constants agree with experiment to within 3%. The known gas phase O-H stretch of NNOH(+) is 3330.91 cm(-1), and the vibrational configuration interaction computed result is 3330.9 cm(-1). Other spectroscopic constants are also provided, as are the rest of the fundamental vibrational frequencies for NNOH(+) and its deuterated isotopologue. This high-accuracy data should serve to better inform future observational or experimental studies of the rovibrational bands of protonated nitrous oxide in the interstellar medium and the laboratory.
authors.affiliation: SETI Institute, 189 Bernardo Avenue, Suite 100, Mountain View, California 94043, USA.
authors.forename: Xinchuan
authors.initials: X
authors.lastname: Huang
authors.forename: Ryan C
authors.initials: RC
authors.lastname: Fortenberry
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Lee