COMPARISON OF AN IMPROVED SEMI-EXPERIMENTAL EQUILIBRIUM STRUCTURE (reSE) OF KETENE TO A HIGH-LEVEL THEORETICAL EQUILIBRIUM STRUCTURE

Smith, Houston H.

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Description

Title

COMPARISON OF AN IMPROVED SEMI-EXPERIMENTAL EQUILIBRIUM STRUCTURE (reSE) OF KETENE TO A HIGH-LEVEL THEORETICAL EQUILIBRIUM STRUCTURE

Author(s)

Smith, Houston H.

Contributor(s)

• McMahon, Robert J.
• Woods, R. Claude
• Stanton, John F.
• Wood, Samuel A.
• Esselman, Brian J.

Issue Date

2023-06-21

Keyword(s)

Structure determination

Abstract

The millimeter-wave spectrum of ketene has been collected and analyzed from 130 GHz to 750 GHz and provided highly precise spectroscopic constants from a sextic S-reduced Hamiltonian. The synthesis of deuteriated samples enabled the spectroscopic measurements of five previously unreported ketene isotopologues. Combined with previous work, this resulted in a new highly precise and accurate semi-experimental (rₑSE) structure for ketene from 32 independent moments of inertia. This rₑSE structure was determined with the experimental rotational constants from all available isotopologues, together with computed vibration-rotation interaction and electron-mass distribution corrections from coupled-cluster singles, doubles, and perturbative triple calculations [CCSD(T)/cc-pCVTZ]. The 2σ uncertainties of the parameters of the rₑSE are ≤ 0.007 A˚ and 0.014◦ for the bond distances and independent angle, respectively. Only S-reduced spectroscopic constants were used in the structure determination, due to a breakdown in the A reduction of the Hamiltonian for the most prolate ketene species. All four structural parameters are in agreement with the “best theoretical estimate” (BTE) calculated from the CCSD(T)/cc-pCV6Z rₑ structure with corrections for extrapolation to the complete basis set, the incomplete treatment of electron correlation, the diagonal Born-Oppenheimer breakdown, and relativistic effects. The discrepancies between the current rₑSE and previously reported rₑSE structures will be discussed.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

Text

Language

eng

Handle URL

https://hdl.handle.net/2142/122386

DOI

https://doi.org/10.15278/isms.2023.6939

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