Absorption Spectrum ofN2in the Extreme Ultraviolet

Improved Fits for the Vibrational and Rotational Constants of Many States of Nitrogen and Oxygen

“…The new fit of the vibrational data is simply a straight line fit to the AG(S) of Verma and Jois Also shown in the figures are new fits to the data, and curves computed using the deperturbed constants of Leoni (1972) and Leoni and Dressler (1972), which are tabulated in both Huber and Herzberg (1979) and Lofthus and Krupenie (1977). Similar data not plotted in Figure 25 can be found in Worley (1943), Gaydon (1944), Lofthus (1957), Tilford and Wilkinson (1964), Yoshino and Tanaka (1977), Yoshino et al (1979) …”

Highly excited states of gerade symmetry in molecular nitrogen

“…Furthermore, it is possible that the lowest rotational level is not discerned, which also may lead to equivocalities. Based on this scheme, three 1 The rotational level energies of the unperturbed ⌺ states are fitted to the following formula:…”

“…The only two states suitable for such an extrapolation are the y 1 ⌸ g , and the k 1 ⌸ g states. Both the a 1 ⌸ g and aЉ 1 ⌺ g ϩ states have vibrational levels in the energy re- Some interactions have been taken explicitly into account. As is clear from the avoided crossings in Fig.…”

“…2,3 This spectrum was extensively studied by Lefebvre-Brion, 4 Dressler, 5 and Carroll, Collins, and Yoshino 6,7 and it is established now that it can be explained in terms of two valence states, bЈ 1 ⌺ u ϩ and b 1 ⌸ u , two Rydberg series c n Ј 1 ⌺ u ϩ and c n 1 ⌸ u which both converge to the first ionization limit and the Rydberg series o n 1 ⌸ u converging to the A 2 ⌸ u excited state of the N 2 ϩ ion. 8 A similar structure is to be expected for the gerade manifold, but investigations in the past have been sparse due to the fact that transitions from the electronic ground state to these gerade states are dipole forbidden.…”

“…At excitation energies between Ϸ100 000 cm Ϫ1 and the first ionization limit ͑125 666 cm Ϫ1 ), molecular nitrogen exhibits a complex and congested spectrum, which was observed in absorption 1 and partly in emission. 2,3 This spectrum was extensively studied by Lefebvre-Brion, 4 Dressler, 5 and Carroll, Collins, and Yoshino 6,7 and it is established now that it can be explained in terms of two valence states, bЈ 1 ⌺ u ϩ and b 1 ⌸ u , two Rydberg series c n Ј 1 ⌺ u ϩ and c n 1 ⌸ u which both converge to the first ionization limit and the Rydberg series o n 1 ⌸ u converging to the A 2 ⌸ u excited state of the N 2 ϩ ion.…”