The spin-orbit interaction in metals and semiconductors

A model for including spin-orbit interaction in setting up the effective potential seen by a valence electron in non-transition metals and semiconductors including liquid metals and alloys is described. It is essentially a generalization of the model potential of Heine and Abarenkov (1964) to take account of the splitting of the observed spectroscopic energy levels due to spin-orbit coupling. Numerical calculations are made for spin-orbit effects in solid germanium and lead: a good agreement with the observed splitting of the valence band in germanium is obtained without any arbitrary parameter. The effects contribute about 5% to the resistivity of liquid lead.