Fitting The High-resolution Spectroscopic Data For Ncncs

Kisiel, Zbigniew

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https://hdl.handle.net/2142/50819 Copy

Description

Title

Fitting The High-resolution Spectroscopic Data For Ncncs

Author(s)

Kisiel, Zbigniew

Contributor(s)

• Billinghurst, Brant E.
• Ross, Stephen Cary
• Tokaryk, Dennis
• De Lucia, Frank C.
• Winnewisser, Manfred
• Winnewisser, Brenda P.

Issue Date

2014-06-19

Keyword(s)

Large amplitude motions, internal rotation

Abstract

NCNCS is a quasi-linear molecule that displays plentiful spectroscopic signatures of transition from the asymmetric top to the linear rotor regime. The transition takes place on successive excitation of the $\nu_7$ bending mode at $ca$ 80 cm$^{-1}$. The unusual spectroscopic manifestations on crossing the barrier to linearity are explained by quantum monodromy and described quantitatively by the generalised semi-rigid bender Hamiltonian.\footnote{B.P.Winnewisser, et al., {\it Phys.~Rev.~Lett.} {\bf 95}. 243002 (2005).}$^,$\footnote{M.Winnewisser, et al., {\it J.~Mol.~Struct.} {\bf 798}, 1 (2006).}$^,$\footnote{B.P.Winnewisser, et al., {\it Phys.~Chem.~Chem.~Phys.} {\bf 12}, 8158 (2010).} \vspace{0.1cm} Nevertheless, analysis to experimental accuracy of the extensive mm-wave spectrum of NCNCS recorded with the FASSST technique has only so far been achieved with the use of separate $J(J+1)$ expansions for each $(v_7, K_a)$ transition sequence.$^c$ In addition, several selective perturbations identified between transition sequences in different vibrational levels$^c$ are still unfitted. Presently we seek effective approximations to the vibration-rotation Hamiltonian that would allow combining multiple sequences into a fit, would allow a perturbation analysis, and could use mm-wave data together with high-resolution infrared measurements of NCNCS made at the Canadian Light Source. \vspace{0.1cm} The understanding of effective fits to low-$K_a$ subsets of rotational transitions in the FASSST spectrum has already allowed confident assignment of the $^{34}$S and both $^{13}$C isotopic species of NCNCS in natural abundance, as will be described.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/50819

DOI

https://doi.org/10.15278/isms.2014.RJ15

Copyright and License Information

Copyright 2014 by the authors. Licensed under a Creative Commons Attribution 4.0 International License. http://creativecommons.org/licenses/by/4.0/

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