Thed ¹ Σ ⁺−c ¹ Π system of NH

Summary

The singlet systems of NH have been excited in a mildly condensed transformer discharge through flowing ammonia gas. The 0-0 bands, 2530 Å ofd ¹ Σ ⁺−c ¹ Π and 3240 Å ofc ¹ Π−a ¹Δ systems, appear with considerable intensity compared to the 4502 Å band of thec ¹ Π −b ¹ Σ ⁺ system. Besides the 2530 Å bands, two weaker bands at 2683 Å and 2516 Å are also excited. They are photographed in the second order of a Jarrell Ash 3·4 m. grating spectrograph at a dispersion of 2·6 Å/mm. Rotational analysis of the two weaker bands show that they belong to thed ¹ Σ ⁺−c ¹ Π system and further supports their assignment as the 0–1 and 1-1 bands. The vibrational and rotational constants derived for thed ¹ Σ ⁺ andc ¹ Π states are,

Table 1