  The motion of fast electrons through the crystal during axial channeling
could be regular and chaotic. The dynamical chaos in quantum systems manifests
itself in both statistical properties of energy spectra and morphology of wave
functions of the individual stationary states. In this report, we investigate
the axial channeling of high and low energy electrons and positrons near [100]
direction of a silicon crystal. This case is particularly interesting because
of the fact that the chaotic motion domain occupies only a small part of the
phase space for the channeling electrons whereas the motion of the channeling
positrons is substantially chaotic for the almost all initial conditions. The
energy levels of transverse motion, as well as the wave functions of the
stationary states, have been computed numerically by the method presented at
previous RREPS. Note that the potential of the elementary cell in (100) plane
of silicon crystal possesses the symmetry of the square. The group theory
methods had been used for classification of the computed eigenfunctions and
identification of the non-degenerate and doubly degenerate energy levels. The
channeling radiation spectrum for the low energy electrons has been also
computed.
