Improved bound-state method for calculating resonance eigenvectors and properties

We derive a new criterion for determining an accurate description of the total wave function at the energy of a resonance in the elastic scattering region from a bound-state representation. The criterion is based on an extension of the stabilization and Harris phase-shift methods. We construct the theoretical framework for a bound-state description of the resonance wave function and exhibit its connection to calculations of the bound-state Green's function.