Nuclear Spin and Hyperfine Structure in Band Spectra

Abstract

PROF. E. HULTHÉN¹ has attempted to show that the splitting of mercury hydride (HgH) band lines into four components, as was found by me² in the (0, 0), (0, 1), (0, 2) and (0, 3) bands and by R. Rydberg³ in the (2, 1) and (3, 2) bands of the ²II½²Σ electronic transition, is a normal isotope effect caused by the difference of masses between the isotopes of mercury. The failure to explain the observed line structure by the usual isotope formula he interprets as indicating the inapplicability of this formula to a mercury hydride molecule, which forms a unique example of an unstable molecule in the ²Σ state. Prof. Hulthén further states that the isotope splittings calculated with the aid of Birge's formula (concerning the vibrational effect) show sufficient agreement with my data, and that there is no need to search for another explanation based on consideration of the magnetic and electric constitution of the nuclei.