The Beta Bands of Nitric Oxide. II. Intensity Relations and Their Interpretation

Relative intensities of band lines.—The equations of Hönl and London predicting the relative intensities of band spectrum lines have been tested with the NO $\beta$ bands (${}_{}{}^2{}_{}{}^{}P\to {}_{}{}^2{}_{}{}^{}P$ transition), a system emitted by an odd molecule, in the same way that they were recently teste d by one of the writers with certain spectra of even molecules. Plates of the $\beta$ bands used n connection with Part I were measured with a densitometer. The data are compared with theory, first, as to order of intensity of lines, and, second, as to quantitative intensities calculated from densities under reasonable assumptions. (Calibration curves of the relationship between light intensity and photographic density for the plates were unfortunately not available.) Best agreement is obtained if it is assumed that the effective temeperature of the active nitrogen source was about 47°C. The observed relative line intnsities are then in essential agreement with those predicted by the Hönl and London equation s. Possible slight departures from exact agreement are discussed. The two sub-bands (${}_{}{}^2{}_{}{}^{}P_1^{}{}_{}{}^{}\to {}_{}{}^2{}_{}{}^{}P_1^{}{}_{}{}^{}$ and ${}_{}{}^2{}_{}{}^{}P_2^{}{}_{}{}^{}\to {}_{}{}^2{}_{}{}^{}P_2^{}{}_{}{}^{}$) in each band are found to be approximately equal in intensity, in agreement with Hund's theory.