Improved determination of the 10-00 rotational frequency of NH3D+ from the high-resolution spectrum of the ν4 infrared band

Abstract

The high-resolution spectrum of the ν4 band of NH 3D+ has been measured by difference frequency IR laser spectroscopy in a multipass hollow cathode discharge cell. From the set of molecular constants obtained from the analysis of the spectrum, a value of 262817 ± 6 MHz (±3σ) has been derived for the frequency of the 10-00 rotational transition. This value supports the assignment to NH3D+ of lines at 262816.7 MHz recorded in radio astronomy observations in Orion-IRc2 and the cold prestellar core B1-bS. © 2013. The American Astronomical Society. All rights reserved.