MILLIMETER-WAVE SPECTROSCOPY OF AMMONIA-WATER WEAKLY BOUNDED COMPLEX

Gyawali, Prakash

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Description

Title

MILLIMETER-WAVE SPECTROSCOPY OF AMMONIA-WATER WEAKLY BOUNDED COMPLEX

Author(s)

Gyawali, Prakash

Contributor(s)

• Kleiner, Isabelle
• Zou, Luyao
• Margulès, L.
• Motiyenko, R. A.

Issue Date

2023-06-19

Keyword(s)

• Large amplitude motions
• internal rotation

Abstract

The broadband rotational spectra of ammonia-water (NH₃-H₂O) complex were measured in the frequency range from 50 to 250 GHz using a supersonic-jet emission spectrometer. The NH₃-H₂O complex exhibits two large amplitude motions (LAMs): almost free internal rotation of ammonia owing to very low torsional barrier (≈ 10 cm−¹), and the inversion of water characterized by relatively high barrier (≈ 700 cm−¹). Because of the latter and taking Doppler-limited resolution of spectrometer into account, we could not observe inversion tunneling splittings of a-type rotational transitions. In total, about 150 rotational transitions of NH₃-H₂O were assigned in this study. They were fitted together with the data from previous studiesᵇ using the "hybrid" Hamiltonian approachᶜ. The analysis is in progress as we are currently trying to modify the characteristics of supersonic expansion in order to achieve higher rotational temperatures and consequently to measure higher Kₐ transitions. The latest results will be presented.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Handle URL

https://hdl.handle.net/2142/122537

DOI

https://doi.org/10.15278/isms.2023.7014

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