The Lyman and Werner Bands of Deuterium

Abstract

The Lyman and Werner bands of D2 have been measured under high resolution and their analysis has been extended. From this analysis the rotational and vibrational levels of the ground state of D2 have been evaluated up to the last vibrational level ν = 21 which lies only 2 cm−1 below the dissociation limit. The deviations of the observed ΔG(ν + 1/2) and Bv values from theoretical values given by Kolos and Wolniewicz on the basis of ab initio calculations are very small but systematic and are probably due to the neglect of nonadiabatic corrections in the theoretical calculations. Similar comparisons have been made for the lower vibrational levels of the B1Σu+ and C1Πu− states. Here the differences between theory and experiment are somewhat larger. The observed electronic excitation energies agree with the theoretical ones within 15 cm−1 for 1Σu+ and 8 cm−1 for 1Πu−.

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium

“…The square root of the second moment of this distribution σ (1) ξk = 0.56 ± 0.14 = 0.56 (14) is not close to unity. We may try to shift the σ (2) ξk to unity by changing error estimation in the following way: σ…”

“…) by two independent methods of the analysis which gave noticeably different results (compare columns 2 and 4 of table 4 from [14]). It is evident that common use of experimental data for five singlet band systems mentioned above may give another set of rovibronic levels for…”

“…The attempts to apply such statistical approach for determination of the energy level values appeared almost simultaneously in atomic (e. g. the spectra of the Er I, Er II [37], Cl II [38] by the inversion method, and the spectra of the Si I [39], Cl I [40] by the iterative method) and in molecular [14,41] spectroscopy when first digital computers became available. It is interesting to note, that in spite of obvious disadvantages of the iterative method (the problems of convergence and lack of the covariance matrix (see p.6 in [42]), its usage can be met in current publications (see e.g.…”

VUV Fourier-transform absorption study of the Lyman and Werner bands in D2

“…From the 1960s, Herzberg and Monfils have studied its absorption spectrum over a wider range with a much higher accuracy, which led to the discovery of new electronic states (B . [11][12][13] In subsequent years Wilkinson, 14 Bredohl and Herzberg, 15 Dabrowski and Herzberg, 16 Takezawa and Tanaka, 17 and Larzillière et al 18 have further extended the spectral investigations using classical spectrometers. Later, after the development of nonlinear optical techniques, tunable extreme ultraviolet (XUV) radiation from a laser-based source was used to yield improved accuracy in the spectroscopy of the D 2 Lyman and Werner bands.…”

Extreme ultraviolet laser calibration of D_2Lyman and Werner transitions

“…Over the years the VUV spectrum of D 2 has been investigated by a number of spectroscopists, namely, Bredohl and Herzberg [1], Dabrowski and Herzberg [2], Takezawa and Tanaka [3], and Larzilliere et al [4], all in connecting wavelength regions. Hinnen et al [5] thereupon performed a study of a limited part of the D 2 spectrum using a tunable laser source in the vacuum ultraviolet at a somewhat better resolution than in the classical spectroscopic studies.…”