HIGH RESOLUTION RAMAN SPECTROSCOPY OF GASES: IX. SPECTRA OF H₂, HD, AND D₂

Abstract

The pure rotational lines and the Q branch lines of the 1–0 vibrational bands of H2, HD, and D2 have been photographed with a 21 ft. grating spectrograph. From these spectra, a complete set of constants for the ν = 0 and 1 levels of all three molecules have been determined. When these constants are combined with Herzberg's results of the forbidden infrared spectra of H2 and HD they lead to improved values of the electronic ground state constants of H2 and HD. The leading terms in the Dunham power series expansion of the potential are calculated for H2 and HD and are found to be mutually consistent. The isotopic relations are obeyed within experimental accuracy, and the small constants De, Be, and He, are in agreement with values given by theoretical formulae.

Orbit-orbit relativistic corrections to the pure vibrational non-Born-Oppenheimer energies of H2

“…As the input data for calculating the parameters of the Dunham's expansion we used 83 spectral transitions ͑includ-ing some duplicated lines measured with different precisions͒ reported in Refs. [25][26][27][28][29][30][31][32][33]. The calculations were performed using a weighted non-linear least-square optimization routine with weights taken as the inverse squares of the uncertainties of the experimental data, u i , ranging from 0.06 up to 0.00008 cm −1 .…”

“…The calculations were performed using a weighted non-linear least-square optimization routine with weights taken as the inverse squares of the uncertainties of the experimental data, u i , ranging from 0.06 up to 0.00008 cm −1 . [25][26][27][28][29][30][31][32][33] To obtain the best fits of Dunham's parameters Y ij from the spectra, we did the following: ͑i͒ the number of fitted parameters was minimized and adjusted to be consistent with the minimum value of the normalized standard deviation and the standard deviation , ͑ii͒ the estimated standard error i , of the fitted parameter i and of the correlation coefficient, cc͑i , j͒, between parameters i and j was optimized to obtain the best fit. Dunham's parameters obtained in the calculations and the estimate of the J =0, v =0→ 1 transition are presented in Table I.…”

High‐Resolution Electron‐Impact Emission Spectrum of H 2 . II. 760–900 A

“…Fortunately, questionable assignments typically occur at levels of the high n J j º 3 and states, whose emission intensities are rather 1& ù 1% ù weak owing to small excitation rates caused by lower populations at higher levels and owing to predissociation and J i autoionization for levels above 14.67 and 15.42 eV, respectively. The rovibrational levels of the X state have been 1& g accurately determined by many experimental measurements (Stoiche † 1957 ;McKellar, Goetz, & Ramsey 1976 ;Jennings & Brault 1982Rich, Jones, & McKellar 1982 ;De Cosmo, Gush, & Halpern 1984) and theoretical calculations (Wolniewicz 1983 ;Hunt, Poll, & Wolniewicz 1984). Experimental uncertainties in the measured line positions and energy levels as small as^0.003 cm~1 have been reported (Chuang & Zare 1987).…”

Ortho-para conversion in the solid hydrogens at high pressures

“…179.065 [24] 354.39 [25] * Consistency of the relationship m rot ( ) J = 2 ; 2 1 m rot ( ) J = was shown by Ramsey [21].…”