Hydrogen atom resonances in strong magnetic fields by complex coordinate rotation and R-matrix methods

Accurate energies and widths corresponding to the lowest m=0 to m=-4 resonances of the hydrogen atom in strong magnetic fields ( gamma =10-1000) are calculated using the complex coordinate rotation and R-matrix methods. The accuracy of the calculations is estimated from the difference observed between the results of both methods. Advantages and drawbacks of the two methods are discussed.