University of Illinois Urbana-Champaign

New high precision linelist of H3+

Hodges, James N.

Content Files
MK06_Abstract.pdf
MK06_Abstract.txt
MK06_Presentation.pptx

Permalink

https://hdl.handle.net/2142/51098

Description

Title
New high precision linelist of H3+
Author(s)
Hodges, James N.
Contributor(s)
  • McCall, Benjamin J.
  • Kocheril, G. Stephen
  • Jenkins, Paul A., II
  • Markus, Charles
  • Perry, Adam J.
Issue Date
2014-06-16
Keyword(s)
Linelists, Lineshapes, Collisions
Date of Ingest
  • 2014-09-17T16:56:06Z
  • 2015-04-14T18:36:40Z
Abstract
As the simplest polyatomic molecule, H$_3^+$ serves as an ideal benchmark for theoretical predictions of rovibrational energy levels. By strictly \textit{ab initio} methods, the current accuracy of theoretical predictions is limited to an impressive one hundredth of a wavenumber,\footnote{O.~L. Polyansky, \textit{et al.} \emph{Phil. Trans. R. Soc. A} (2012), \textbf{370}, 5014--5027.} which has been accomplished by consideration of relativistic, adiabatic, and non-adiabatic corrections to the Born-Oppenheimer PES. More accurate predictions rely on a treatment of quantum electrodynamic effects, which have improved the accuracies of vibrational transitions in molecular hydrogen to a few MHz.\footnote{J. Komasa, \emph{et al.} \emph{J. Chem. Theor. Comp.} (2011), \textbf{7}, 3105--3115.} High precision spectroscopy is of the utmost importance for extending the frontiers of \textit{ab initio} calculations, as improved precision and accuracy enable more rigorous testing of calculations. Additionally, measuring rovibrational transitions of H$_3^+$ can be used to predict its forbidden rotational spectrum. Though the existing data can be used to determine rotational transition frequencies, the uncertainties are prohibitively large.\footnote{C.~M. Lindsay, B.~J. McCall, \emph{J. Mol. Spectrosc.} (2001), \textbf{210}, 66--83.} Acquisition of rovibrational spectra with smaller experimental uncertainty would enable a spectroscopic search for the rotational transitions. The technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy, or NICE-OHVMS has been previously used to precisely and accurately measure transitions of H$_3^+$, CH$_5^+$, and HCO$^+$ to sub-MHz uncertainty.\footnote{J.~N. Hodges, \textit{et al.} \emph{J. Chem. Phys.} (2013), \textbf{139}, 164201.} A second module for our optical parametric oscillator has extended our instrument's frequency coverage from 3.2-3.9 $\mu$m to 2.5-3.9 $\mu$m. With extended coverage, we have improved our previous linelist by measuring additional transitions.
Publisher
International Symposium on Molecular Spectroscopy
Type of Resource
text
Genre of Resource
Conference Paper / Presentation
Language
English
Permalink
http://hdl.handle.net/2142/51098
DOI
https://doi.org/10.15278/isms.2014.MK06
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/

Owning Collections

Abstracts & Presentations - 2014 International Symposium on Molecular Spectroscopy PRIMARY