Accurate ab-Initio Quartic Force Fields for the Sulfur Compounds H2S, CS2, OCS, and CS

✍ Scribed by J.M.L. Martin; J.P. Francois; R. Gijbels

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 645 KB
• Volume: 169
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.1995.1037

✦ Synopsis

The quartic force fields of the (\mathrm{H}{2} \mathrm{~S}, \mathrm{CS}{2}, \mathrm{OCS}), and (\mathrm{CS}) molecules have been computed using the (\operatorname{CCSD}(\mathrm{T})) augmented coupled cluster method and (s p d f) and spdfg basis sets. Neglect of core correlation results in fairly noticeable error in computed geometries, but does not seem to affect other spectroscopic constants substantially. Computed results for (\mathrm{H}{2} \mathrm{~S}) are in excellent agreement with experiment; of the available experimental force fields, our calculations favor the very recent one by Kozin and Jensen. Good agreement is also seen for (\mathrm{CS}{2}), except for the (\sigma_{g}) stretch. After correction for multiple Fermi resonances, excellent results are also obtained for OCS. Residual error in CS can be traced back almost entirely to overestimation of the bond distance. ci 1995 Academic Press, Inc