High-Resolution Band Structure and theE2Peak in Ge

We find evidence that the $E_2$ optical peak in Ge arises from transitions in a well-defined, limited region inside the Brillouin zone. This conclusion is compatible with the recent experimental results of Aspnes. The region of interest is not on symmetry lines, but it is close to the ($\frac{3}{4}$, ¼,¼) special point determined by Chadi and Cohen. The calculated modulated reflectivity, density of states, and interband masses are in good agreement with experiment.