As described in the preceding Letter, hereafter referred to as DBG, the hydrogen atom in a magnetic field has attracted unusual interest because it is among the simplest nonseparable systems that are physically realizable, because it is one of the small number of systems whose classical motion displays chaotic behavior in regimes where accurate quantum-mechanical calculations are possible, and because it can be studied experimentally with high precision. The simplicity of this problem is deceiving, however, for carrying forward theory and experiment have both proven to be formidable undertakings. DBG describes a breakthrough in the problem of calculating the positive-energy spectrum at laboratorysized magnetic fields. We report here the results of a comparison of calculated spectra with spectra observed experimentally by the MIT group who are the co-authors of this joint paper.

The most successful previous study of this kind was a comparison of the observed and computed spectrum for deuterium by Holle et al. for energy in the range of −190 to −20 cm−1. However, the experimental resolution was too low to achieve fully resolved spectra at the highest energies, and the computational method was limited to the negative-energy region. The work described here overcomes these limitations.