1. Rotational spectra and equilibrium structures of H2SiS and Si2S.
- Author
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McCarthy, Michael C., Gottlieb, Carl A., Thaddeus, Patrick, Thorwirth, Sven, and Gauss, Jürgen
- Subjects
ROTATIONAL motion ,SPECTRUM analysis ,EQUILIBRIUM ,MOLECULAR structure ,SILICON ,SULFIDES ,MICROWAVE spectroscopy ,MOLECULAR beams - Abstract
The rotational spectra of two small silicon sulfides, silanethione H
2 SiS and the disilicon sulfide ring Si2 S, have been detected in the centimeter band by Fourier transform microwave spectroscopy of a molecular beam; lines of H2 SiS were also observed in the millimeter band up to 377 GHz in a glow discharge. Precise rotational and centrifugal distortionconstants have been determined for the normal and a number of the more abundant rare isotopic species of both closed-shell molecules. Theoretical equilibrium (re ) structures of H2 SiS and Si2 S were derived from coupled-cluster calculations that included triple and quadruple excitations, core correlation, and extrapolation to the basis-set limit. The re structures agree to within 5×10-4 Å and 0.1° with empirical equilibrium (re emp ) structures derived from the experimental rotational constants, combined with theoretical vibrational and electronic corrections. Both H2 SiS and Si2 S are good candidates for radioastronomical detection in the circumstellar shells of evolved carbon-rich stars such as IRC+10216, because they are fairly polar and are similar in composition to the abundant astronomical molecule SiS. [ABSTRACT FROM AUTHOR]- Published
- 2011
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