Rotational analysis of the molecular hydrogen triplet 3s,d complex revisited

Abstract

The emission spectrum of neutral diatomic hydrogen has been recorded at Doppler width limited resolution by Fourier transform spectroscopy in the spectral range 1800–22,500 cm⁻¹. Rotational analysis of the triplet systems involving the electronic states c ³Π _u , , , and the 3s,d complex has been carried out in order to determine precise rovibronic energies (with v = 0 to 3) of the 3s,d complex. This new observation agrees with the earlier calculations within a few cm⁻¹ and corrects incorrect ‘observed’ level energies published for v = 2 and 3, by about 50 and 90 cm⁻¹, respectively.

Keywords:

• H₂
• 3 _s,d complex
• Observed vibronic energies
• Emission FT spectrum

Acknowledgements

We thank Dr Ch. Jungen and Professor S. C. Ross for having pointed out this problem to our attention, and for the encouragement they have provided to us for reconsidering the rotational analysis of the hydrogen emission spectrum. We also thank the French research program P. C. M. I. for partial financial support.