The Electric Quadrupole Spectra Of Diatomic Molecules

Somogyi, Wilfrid

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https://hdl.handle.net/2142/111446 Copy

Description

Title

The Electric Quadrupole Spectra Of Diatomic Molecules

Author(s)

Somogyi, Wilfrid

Contributor(s)

Yurchenko, Sergei N.

Issue Date

2021-06-22

Keyword(s)

Linelists

Abstract

Owing to their molecular symmetry, many transitions of homonuclear diatomic molecules are forbidden in the electric dipole approximation. Instead their spectra are dominated by higher order transition moments, including the magnetic dipole moment and electric quadrupole moment. \begin{wrapfigure}{r}{0pt} \includegraphics[width=.4\linewidth]{H2XQMhitran.eps} \end{wrapfigure} Here we present a new implementation of electric quadrupole transition moments in \textsc{Duo}\footnote{S.~N. Yurchenko, L.~Lodi, J.~Tennyson, A.~V. Stolyarov, \emph{Comput. Phys. Commun.}, 2016, \textbf{202}, 262 -- 275; publicly available at \textit{https://github.com/Trovemaster/Duo}.}. The implementation is validated against the highly accurate linelist of Roueff et al. \footnote{The full infrared spectrum of molecular hydrogen, Astron. Astrophys, 630 (2019)} for rovibrational transitions of the hydrogen molecule. We also perform ab initio calculations for potential energy curves (PECs), electric quadrupole moment curves (EQCs), and spin-orbit coupling curves (SOCs) and demonstrate rovibronic linestrength calculations for the three lowest lying states ($X^3\Sigma_g^-$, $a^1\Delta_g$ and $b^2\Sigma_g^+$) of molecular oxygen. Further demonstrations are provided for various other molecules of interest, including CO and HF as part of the ExoMol project \footnote{J.~Tennyson et al. \emph{J. Quant. Spectrosc. Radiat. Transf.}, 2020, \textbf{255}, 107228; \textit{www.exomol.com}.}. Absorption cross-sections are calculated using the \textsc{ExoCross} program\footnote{S.~N. {Yurchenko}, A.~F. {Al-Refaie}, J.~{Tennyson}, \emph{Astron. Astrophys};, 2018, \textbf{614}, A131; publicly available at \textit{https://github.com/Trovemaster/ExoCross}.}.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Permalink

http://hdl.handle.net/2142/111446

DOI

10.15278/isms.2021.TF03

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