Abstract:
Analytical expressions for the dispersion of electron bands are obtained by the method of Green's functions in the tight-binding approximation. A parabolic approximation of the spectrum is proposed, within the framework of which the values of the effective mass of carriers and the quantum capacity are determined. The problem of local states of defects is considered using the Koster–Slater and Haldane–Anderson models. Analytical estimates of the characteristic phonon frequencies and elastic constants are given. The results are compared with the calculated data of other authors.