Knowledge Bank

Four spectra of natural OCS have been recorded for the Handbook of Infrared Standards published by G. Guelachvili and K.N. Rao. [FIGURE] The spectra have been calibrated within 2 $10-5cm-1$ near $2000cm-1$ to 4 $10-5cm-1$ near $3000cm-1$. Practically all lines have been assigned. Thirteen isotopic species have been identified, some of them with an abundance of 0.002%. As the J(J+1) expansion of energies frequently diverges from anharmonic and $\ell$-type resonances, the analysis of each band has been applied on the deviations between the calculated frequencies from our global $analysis[1]$ and the observed frequencies, according to a polynomial of order 1 or 2 (rarely 3) in J[J+1]. The new data have been introduced in the global analysis. Dealing with the intensities, we obtain smoothed values for the line strengths and finally the band strengths which appear to be in good agreement ($\pm 20$%) with the absolute measurements of R.H. $Kagann[2]$.