Schrödinger operators with symmetries II systems with spin

We extend the results on the spectra of Schrödinger operators with symmetries contained in the preceding paper Schrödinger operators with symmetries to systems with spin with interactions of spin-orbit type. Thus we determine the essential spectrum under the assumption of relative compactness and show the absence of singular continuous spectrum for operators with dilation-analytic interactions.Finally we prove the absence of eigenvalues for a system of electrons with spin-orbit interactions and as a consequence the existence of an infinity of eigenvalues for each symmetry type in an atom with such interactions.