Some relationships between singlets and triplets in the spectra of two electron systems
The Darwin-Pauli treatment of the electron is applied to the Schroedinger equation for a two electron system. The results show that the division into singlets and triplets is justified only as a limiting case. Expressions are derived which give the position of the levels, the Zeeman effect pattern, and the intensities of the lines when the division into singlet and triplet cannot strictly be made. These expressions are shown to give the observed facts of several spectra.
©1929 The American Physical Society. Received 15 November 1928. This work was carried out in the Institute for Theoretical Physics at Leipzig under the direction of Professor Heisenberg to whom I am much indebted for his kind assistance. I am also indebted to the John Simon Guggenheim Memorial Foundation for the opportunity of studing in Leipzig.