Skip to Main content Skip to Navigation
Journal articles

Understanding (coupled) large amplitude motions: the interplay of microwave spectroscopy, spectral modeling, and quantum chemistry

Abstract : A large variety of molecules contain large amplitude motions (LAM), inter alia internal rotation and inversion tunneling, resulting in tunneling splittings in their rotational spectrum. We will present the modern strategy to study LAMs using a combination of molecular jet Fourier transform microwave spectroscopy, spectral modeling, and quantum chemical calculations to characterize such systems by the analysis of their rotational spectra. This interplay is particularly successful in decoding complex spectra revealing LAMs and providing reference data for fundamental physics, astrochemistry, atmospheric/environmental chemistry and analytics, or fundamental research in physical chemistry. Addressing experimental key-aspects, a brief presentation on the two most popular types of state-of-the-art Fourier transform microwave spectrometer technology, i.e. pulsed supersonic jet expansion based spectrometers employing narrow-band pulse or broad-band chirp excitation, will be given first. Secondly, the use of quantum chemistry as a supporting tool for rotational spectroscopy will be discussed with emphasis on conformational analysis. Several computer codes for fitting rotational spectra exhibiting fine structure arising from LAMs are discussed with their advantages and drawbacks. Furthermore, a number of examples will provide an overview on the wealth of information that can be drawn from the rotational spectra, leading to new insights on the molecular structure and dynamics. The focus will be on the interpretation of potential barriers and how LAMs can act as sensors within molecules to help us understand molecular behavior in the laboratory and nature.
Document type :
Journal articles
Complete list of metadata
Contributor : Ha Vinh Lam Nguyen Connect in order to contact the contributor
Submitted on : Friday, March 26, 2021 - 2:00:45 PM
Last modification on : Thursday, April 7, 2022 - 1:58:17 PM
Long-term archiving on: : Sunday, June 27, 2021 - 6:43:12 PM


Book chapter_HAL.pdf
Files produced by the author(s)




Ha Vinh Lam Nguyen, Isabelle Kleiner. Understanding (coupled) large amplitude motions: the interplay of microwave spectroscopy, spectral modeling, and quantum chemistry. Physical Sciences Reviews, De Gruyter, In press, ⟨10.1515/psr-2020-0037⟩. ⟨hal-03182535⟩



Record views


Files downloads