Knowledge Bank

A $\chi 2$ test has been used to obtain improved molecular constants for the A $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi -X2 \Sigma$ system of the $C12N14$ molecule. It is found that these constants predict wavenumbers that agree with the observed values to within 0.1 \AA for the rotational lines of the lowere vibrational bands up to $N^\{\backslash prime\}^\{\backslash prime\}=80$ and for the higher bands up to $N^\{\backslash prime\}^\{\backslash prime\}\; =\; 50$. The rotational lines of the (2,0) and (3,1) vibration-bands of the $C12N14$ radical have also been computed with these spectroscopic constants and the wavenujbers agree within 0.1 \AA, if the electronic isotope shift between the $C12$ $N14$ and $C13N14$ molecules is 0.2 \AA In the present calculation the effect of degenerate perturbations between the $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Pi$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}\Sigma$ states is included.