Knowledge Bank

Fourier Transform spectra have been obtained for $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C18O2$ in the regions of $\nu 2(16 \mu$m) and $\nu 3(4.3 \mu$m) at a resolution of $0.04cm-1$. From a least-square fit of the P and R branch lines for the transitions, values have been obtained for the molecular spectroscopic constants. Based on the derived constants, the calculated wavenumbers for the P And R branch lines for both the $(0110-0000)$ and $(0001-0000)$ transitions agree with the observed positions within $\pm 0.003$ $cm-1$. We have also observed the different bands $\nu 1-\nu 2$ and $(\nu 3+\nu 2)-\nu 2$. From an analysts of these transitions we have obtained values for the $\ell$-doubling constant for $\nu 2$ and the location of the Fermi resonance levels $(10000,0200)$.