1. For a review of the status of the H2
+ and H2 problems prior to the new quantum mechanics see Van Vleck, Quantum Principles and Line Spectra, p. 88. Also discussion by Kemble in last chapter of National Research Council Report on “Molecular Spectra in Gases.”
2. Burrau, Danske Vidensk. Selskab. Math.-fys. Meddel., 7, 14, Copenhagen (1927).
3. Born and Heisenberg, Ann. Physik, 74, 1 (1924).
4. Van Vleck and Hutchisson, Physic. Rev., 28, 1022 (1926).
5. Hund, Zs. Physik, 40, 742 (1927).