VACUUM-ULTRAVIOLET EMISSION AND ABSORPTION SPECTRUM OF THE NO MOLECULE: THE 2Δ STATES AND THEIR INTERACTIONS

Abstract

The emission spectrum of NO between 1 600 and 1 400 Å has been studied with a 1-m vacuum spectrograph. It consists of the two types of mutually perturbing 2Δ–X2Π bands already known from the much more complex absorption spectrum: the Rydberg systems F2Δ–X2Π, N2Δ–X2Π and the non-Rydberg system B′ 2Δ–X2Π. The interactions between the excited states of different electron configurations are of special interest. The matrix elements H = Hvib ∙ He have been obtained from detailed rotational analyses, a "deperturbation" in two steps has been carried out, and constants for the deperturbed 2Δ states are given. With calculated overlap integrals Hvib, the electronic configuration interaction energy He is derived. "Crossing" potential energy curves have been shown to be the appropriate zero-order approximation when [Formula: see text]. The phase of the interaction, i.e. the sign of He, has been deduced from the perturbed intensities of the observed bands.