Structure of the Band Spectra of the Hydrogen and Helium Molecules

Abstract

IN the spectrum of the hydrogen molecule many regularities have been found recently, especially by Richardson and his co-workers. In a note in the Zs. f. Physik I suggested an interpretation of those regularities based mainly on the theory of band complexes and the analogy with the helium band spectrum. The analogy was incomplete in so far as the bands found in the spectrum of the hydrogen molecules are analogous to helium bands which can be predicted from theoretical considerations, but which had not been actually found. I have found these missing helium bands now. Their structure is exactly analogous to that of the hydrogen bands given by Richardson and Davidson (Proc. Roy. Soc., A, 123, 54, 466, A, 124, 50, 69), as will be best apparent from a description of their peculiarities. From the red to the violet we have the following branches: