Optimized geometries and complete, scaled quadratic force fields of HCOCN and HCSCN have been determined at different theoretical levels (HF/4-21, HF/6-31G**; geometries also at MP2/6-31G** and MP2/6-311G**). Frequencies calculated from the force fields confirm, with one exception, the assignment of the vibrational spectrum of HCOCN. The vibrational fundamentals calculated for HCSCN (accurate within about 50 cm-1) could direct a spectroscopy study aimed at determining them. Calculated rotational and quartic centrifugal distortion (QCD) constants are in good agreement with the experimental data for both molecules, but QCD constants only after scaling of the force fields.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry