The relativistic valence and conduction band edges of trigonal Te and Se

Relativistic ab initio level bands are presented for trigonal Te and Se in the vicinity of the valence band maxima and conduction band minima. The agreement with the experimental k · p band models of Te is close. The differences are associated with the missing Darwin and mass-velocity terms in the k · p models. There are distinct differences between the calculated band edges for Se and the model proposed by Moreth.