SYMMETRIES OF HIGHLY EXCITED ATOMIC-HYDROGEN - QUADRATIC ZEEMAN SPLITTING DISTORTED BY FINE-STRUCTURE EFFECTS

Using the classical mechanical perturbation approach and semiclassical quantization rules we explain the spectrum of atomic hydrogen in a we ak magnetic field in which fine structure of levels cannot be neglecte d. The general pattern of the spectrum turns out to be very different from the nonrelativistic scheme. In particular, we point out the prese nce of another type of ''exponentially narrow'' doubler.