Highly Accurate Quantum-chemical Calculations For The Interstellar Molecules C3 And L-c3h+

Botschwina, Peter

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https://hdl.handle.net/2142/51044 Copy

Description

Title

Highly Accurate Quantum-chemical Calculations For The Interstellar Molecules C3 And L-c3h+

Author(s)

Botschwina, Peter

Contributor(s)

• Oswald, Rainer
• Sebald, Peter
• Stein, Christopher
• Schröder, Benjamin

Issue Date

2014-06-19

Keyword(s)

Mini-symposium: Astronomical Molecular Spectroscopy in the Age of ALMA

Abstract

Composite potential energy surfaces with coupled-cluster contributions up to CCSDTQP were constructed for C$_3$ and l-C$_3$H$^+$ and used in the calculation of spectroscopic properties. The use of very large AO basis sets and the consideration of higher-order correlation beyond CCSD(T) is of utmost importance for C$_3$ in order to arrive at quantitative spectroscopic data. The first detection of l-C$_3$H$^+$ in the interstellar medium was reported by Pety et al.,\footnote{J. Pety, P. Gratier, V. Guzm\'{a}n, E. Roueff, M. Gerin et al., \textit{Astron. Astrophys.} \textbf{2012}, \textit{A68}, 1-8.} who attributed 9 radio lines observed in the horsehead photodissociation region to that species. That assignment was questioned by the recent theoretical work of Huang et al.\footnote{X. Huang, R. C. Fortenberry, T. J. Lee, \textit{Astrophys. J. Lett.} \textbf{2013}, \textit{768:L25}, 1-5.} However, our more accurate calculations are well in support of the original assignment. The calculated ground-state rotational constant is $B_0 = 11248$~MHz, only $0.03\%$ off from the radio astronomical value of $11244.9512\pm0.0015$~MHz. The ratio of centrifugal distortion constants D$_0$(exp.)/D$_e$(theor.) of 1.8 is quite large, but reasonable in comparison with C$_3$O\footnote{P. Botschwina, R. Oswald, \textit{J. Chem. Phys.} \textbf{2008}, \textit{129}, 044305.} and C$_3$.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

Permalink

http://hdl.handle.net/2142/51044

DOI

https://doi.org/10.15278/isms.2014.RA02

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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