Knowledge Bank

The $\nu 2$ and $\nu 3$ bands of $NO2$ have been obtained under high resolution. The $\nu 2$ band has been completely analyzed and accurate constants calculated. The observed frequencies have been fitted using the Watson Hamiltonian. On combining data from the microwave spectrum, the $\nu 2$ and $2\nu 3$ IR bands improved ground state constants were obtained. The band center and rotational constants are:[FIGURE] Spin splitting has been observed for transitions with $K\ge 1$ and has been accounted for satisfactorily within a symmetric top approximation; spin splitting constants will be reported. The $\nu 3$ band has been fully calibrated. It is now being analyzed and it is hoped that a preliminary set of band constants will be available at the time this paper will be presented. The equilibrium structure has been calculated and will be reported.