Continuum spectrum of an atom or molecule in a magnetic field

Abstract

We calculate the positive-energy spectrum of both hydrogen and lithium atoms in a field of 6.1 T and we show how such spectra can be obtained for an atom or molecule in an arbitrary strength magnetic field. The theory combines quantum-defect theory, R-matrix propagation, and two-dimensional frame transformations. Much of the resonance structure in the continuum can be understood in terms of complex perturbed Rydberg series.